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Networking and/with the computer
László Kálmán1 Csaba Oravecz1 Péter Szigetvári1,2
1Research Institute for LinguisticsHungarian Academy of Sciences
2Department of English LinguisticsEötvös Loránd University
Lecture 6–7. / 14, 21 Oct, 2009
Kálmán, Oravecz, Szigetvári Networking
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
✌
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
✌ → live demo on stage!
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
✌ → live demo on stage!
✔
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
✌ → live demo on stage!
✔ → correct/advantage/encouraged
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
✌ → live demo on stage!
✔ → correct/advantage/encouraged
✘
Kálmán, Oravecz, Szigetvári Networking
Introduction
abstract
this lecture tells you about
• setting up and connecting to a Local Area Network
• the World Wide Web
• using computer networks for common tasks such asconnecting to remote machines, transferring files, sendingmail
The meaning of symbols used
✌ → live demo on stage!
✔ → correct/advantage/encouraged
✘ → incorrect/disadvantage/discouraged
Kálmán, Oravecz, Szigetvári Networking
Introduction Sample exam question
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Introduction Sample exam question
Sample exam question
How much net work could a network work, if a networkcould net work?
Kálmán, Oravecz, Szigetvári Networking
Introduction Sample exam question
Typical computer environments of students
Kálmán, Oravecz, Szigetvári Networking
Introduction Sample exam question
Typical computer environments of students
Figure: Home “lab”
Kálmán, Oravecz, Szigetvári Networking
Introduction Sample exam question
Typical computer environments of students
Figure: Home “lab” Figure: University lab
Kálmán, Oravecz, Szigetvári Networking
Computer networking Sharing information
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Computer networking Sharing information
Isolation is secure but inconvenient
Information is there to be shared• efficiently
• quickly
• in large amounts
• cost effectively.
Kálmán, Oravecz, Szigetvári Networking
Computer networking Sharing information
Isolation is secure but inconvenient
Information is there to be shared• efficiently
• quickly
• in large amounts
• cost effectively.
Most of data on computers is information. To share thiscomputers must communicate with each other. How?
Kálmán, Oravecz, Szigetvári Networking
Computer networking Sharing information
Network, my choice is.
Link computer systems together, we must.
Kálmán, Oravecz, Szigetvári Networking
Computer networking Sharing information
Network, my choice is.
Computer network
Two or more computers that are linked in order to shareresources (eg. printers), exchange files, allow electroniccommunications.
Kálmán, Oravecz, Szigetvári Networking
Computer networking Sharing information
Network, my choice is.
Computer network
Two or more computers that are linked in order to shareresources (eg. printers), exchange files, allow electroniccommunications.
Link types
• cables
• telephone lines
• radio waves
• satellites
• infrared light beams
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network topology
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network topology
The physical topology of a network refers to . . .
the configuration of cables, computers, and other peripherals.
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network topology
The physical topology of a network refers to . . .
the configuration of cables, computers, and other peripherals.
Figure: Star topology
Star topology
• easy to install and wire• no disruptions to the network
when connecting or removingdevices
• easy to detect faults and toremove parts
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types (some, not all)
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types (some, not all)
Figure: LAN
Local Area Network• confined to a limited geographic
area (building, college campus)• high data traffic• uses Ethernet technology• communication standard
(protocol): TCP/IP
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types (some, not all)
Figure: LAN
Local Area Network• confined to a limited geographic
area (building, college campus)• high data traffic• uses Ethernet technology• communication standard
(protocol): TCP/IP
Wireless LAN
Using high frequency radio waves ittransmits data over the air minimizingthe need for wired connections. WLANsgive users mobility: they allowconnection to a local area networkwithout having to be physicallyconnected by a cable.
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types
Figure: WAN
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types
Figure: WAN
Wide Area Network• covers a broad
geographical area
• combines multiple LANs
• largest: ?
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types
Figure: WAN
Wide Area Network• covers a broad
geographical area
• combines multiple LANs
• largest: Internet
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Network types
Figure: WAN
Wide Area Network• covers a broad
geographical area
• combines multiple LANs
• largest: Internet
• may be built for oneparticular organization tobe private or by Internetservice providers (ISP) toprovide connections froman organization’s LAN tothe Internet
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Typical students’ wishes
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Typical students’ wishes
At home
I want to set up a small WLAN for my home. (I have a desktopPC, two notebooks, a network printer and a fridge.) How can Ido it and what devices will I need?
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Typical students’ wishes
At home
I want to set up a small WLAN for my home. (I have a desktopPC, two notebooks, a network printer and a fridge.) How can Ido it and what devices will I need?
At the university
I’m sitting in the university lab in front of a thin display. Theremust be some program running since there is a small window inthe middle like this . . .
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Login windows
like this . . .
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Login windows
like this . . . or like this . . .
Kálmán, Oravecz, Szigetvári Networking
Computer networking Network types and topologies
Setting up a home LAN
?cable/ADSL modem
router(+switch)+Access
Point (AP)
����
Figure: This will hopefully be a working home LAN
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Network interfaces: ethernet card
To connect to a network computers must have some network interface. Fora desktop PC it is commonly an ethernet card, with a designated sockettype and cable.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Network interfaces: ethernet card
To connect to a network computers must have some network interface. Fora desktop PC it is commonly an ethernet card, with a designated sockettype and cable.
Figure: Ethernet network cardFigure: Network cable
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Network interfaces: wireless
Wireless network interface controller (WNIC)
A network card which connects to a radio-based computernetwork.
No image :( Why?
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Network interfaces: wireless
Wireless network interface controller (WNIC)
A network card which connects to a radio-based computernetwork.
No image :( Why?
Most common in notebook computers (and Macworkstations) and there it is integrated on the motherboard.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Network interfaces: wireless
Wireless network interface controller (WNIC)
A network card which connects to a radio-based computernetwork.
No image :( Why?
Most common in notebook computers (and Macworkstations) and there it is integrated on the motherboard.Today it’s impossible to buy a laptop which does not have it!
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Network interfaces: wireless
Wireless network interface controller (WNIC)
A network card which connects to a radio-based computernetwork.
No image :( Why?
Most common in notebook computers (and Macworkstations) and there it is integrated on the motherboard.Today it’s impossible to buy a laptop which does not have it!
For a desktop PC it could just be yet another PCI card.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
01-23-45-fc-89-ab
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
01-23-45-fc-89-ab
00:08:74:4C:7F:1D
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
01-23-45-fc-89-ab
00:08:74:4C:7F:1D
Q: How many possible addresses are there?
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
01-23-45-fc-89-ab
00:08:74:4C:7F:1D
1612= 248
= 281, 474, 976, 710, 656
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
01-23-45-fc-89-ab
00:08:74:4C:7F:1D
1612= 248
= 281, 474, 976, 710, 656
• Not expected to be saturated before 2100.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
MAC address
Media Access Control address
A unique identifier attached to most forms of networkingequipment including the interfaces we’ve talked about. Printedin hexadecimal format:
01-23-45-fc-89-ab
00:08:74:4C:7F:1D
1612= 248
= 281, 474, 976, 710, 656
• Not expected to be saturated before 2100.
We will see that you might well need this information. . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Home network checklist
?cable/ADSL modem
router(+switch)+Access
Point (AP)
����
Figure: So far, so good. . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Home network checklist
?cable/ADSL modem
router(+switch)+Access
Point (AP)
��
Figure: So far, so good. . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Home network checklist
?cable/ADSL modem
router(+switch)+Access
Point (AP)
��
Figure: So far, so good. . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Home network checklist
?cable/ADSL modem
router(+switch)+Access
Point (AP)
����
Figure: So far, so good but some devices are still missing. . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Modems providing broadband internet access
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Modems providing broadband internet access
Cable modemprovides network access by using the cable televisioninfrastructure.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Modems providing broadband internet access
Cable modemprovides network access by using the cable televisioninfrastructure.
ADSL (Asymmetric Digital Subscriber Line) modem
provides digital data transmission over the wires of a localtelephone network.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Modems providing broadband internet access
Cable modemprovides network access by using the cable televisioninfrastructure.
ADSL (Asymmetric Digital Subscriber Line) modem
provides digital data transmission over the wires of a localtelephone network.
Internet Service Provider (ISP)
The organization that sells access to the Internet and relatedservices.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
We
have already contacted our ISP and the service is up and running now athome.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
We
have already contacted our ISP and the service is up and running now athome.
Still to be done
The ISP provides you with a single cable line through the modem devicea
to which we can connect with one computer having an ethernet card.That means you are just a node in the ISP’s LAN/WAN! But. . .
aCable modems remain the property of the ISP.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
We
have already contacted our ISP and the service is up and running now athome.
Still to be done
The ISP provides you with a single cable line through the modem devicea
to which we can connect with one computer having an ethernet card.That means you are just a node in the ISP’s LAN/WAN! But. . .
• We take a fancy to wireless networking.
aCable modems remain the property of the ISP.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
We
have already contacted our ISP and the service is up and running now athome.
Still to be done
The ISP provides you with a single cable line through the modem devicea
to which we can connect with one computer having an ethernet card.That means you are just a node in the ISP’s LAN/WAN! But. . .
• We take a fancy to wireless networking.• We need to have all our computers with access to the internet.
aCable modems remain the property of the ISP.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
We
have already contacted our ISP and the service is up and running now athome.
Still to be done
The ISP provides you with a single cable line through the modem devicea
to which we can connect with one computer having an ethernet card.That means you are just a node in the ISP’s LAN/WAN! But. . .
• We take a fancy to wireless networking.• We need to have all our computers with access to the internet.• All of our home devices should be able to communicate with each
other (printer and fridge incl.).
aCable modems remain the property of the ISP.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection established. . .
We
have already contacted our ISP and the service is up and running now athome.
Still to be done
The ISP provides you with a single cable line through the modem devicea
to which we can connect with one computer having an ethernet card.That means you are just a node in the ISP’s LAN/WAN! But. . .
• We take a fancy to wireless networking.• We need to have all our computers with access to the internet.• All of our home devices should be able to communicate with each
other (printer and fridge incl.).• After all, that’s the whole point of a home LAN!
aCable modems remain the property of the ISP.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Useful info
The speed of data transfer through the network is measured inbit/s (bps). 128 kbit/s (Kbps) today is considered low even forhome networking. ISPs offer services up to several Mbps butthis has its price. To download high quality movies you willneed this several Mbps, nevertheless. For average homeinternet use, however, a basic 1 Mbps download bandwidthservice will suffice.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection to be established. . .
We have two LANs here to deal with:
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection to be established. . .
We have two LANs here to deal with:• the ISP’s LAN/WAN
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection to be established. . .
We have two LANs here to deal with:• the ISP’s LAN/WAN
• our home LAN
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Connection to be established. . .
We have two LANs here to deal with:• the ISP’s LAN/WAN
• our home LAN
Only the former is connected to the Internet, so we have tomake a link between our home LAN and the ISP’s LAN/WAN(“represented” by the modem). For this we need a specialdevice . . .
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Home network checklist
?cable/ADSL modem
router(+switch)+Access
Point (AP)
����
Figure: So far, so good
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
Home network checklist
?cable/ADSL modem
router(+switch)+Access
Point (AP)
����
Figure: So far, so good and there are no devices missing!?
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
The network fridge, it is.
The Fridge with network interface, in our home, we haveyet not.
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
(Wireless) router
Figure: The back of a wirelessrouter
Multiple devices in one
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
(Wireless) router
Figure: The back of a wirelessrouter
Multiple devices in one
• switch for the LAN(connecting devices within)
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
(Wireless) router
Figure: The back of a wirelessrouter
Multiple devices in one
• switch for the LAN(connecting devices within)
• access point for thewireless network(connecting it to the wiredLAN)
Kálmán, Oravecz, Szigetvári Networking
Back to the hardware Network devices
(Wireless) router
Figure: The back of a wirelessrouter
Multiple devices in one
• switch for the LAN(connecting devices within)
• access point for thewireless network(connecting it to the wiredLAN)
• router: junction betweentwo or more networks totransfer data packetsamong them
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
• use the network: send and recieve data
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
• use the network: send and recieve data
• to whom and where?
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
• use the network: send and recieve data
• to whom and where?
• MAC address ≈ personal identification number; tells youwho you are but not where you are
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
• use the network: send and recieve data
• to whom and where?
• MAC address ≈ personal identification number; tells youwho you are but not where you are
• postal address
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
• use the network: send and recieve data
• to whom and where?
• MAC address ≈ personal identification number; tells youwho you are but not where you are
• postal address → IP Address
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sending data
Hardwarewise everything is set up . . .
• use the network: send and recieve data
• to whom and where?
• MAC address ≈ personal identification number; tells youwho you are but not where you are
• postal address → IP Address
Data fragments
Data through the network is split up into packets, each labeledwith the complete destination address.
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Network addresses
Figure: Network addresses are like house numbers and street names
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Address representation
IPv4: 32-bit (4-byte) addresses. Address space: ?
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Address representation
IPv4: 32-bit (4-byte) addresses. Address space: 4,294,967,296.
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Address representation
IPv4: 32-bit (4-byte) addresses. Address space: 4,294,967,296. Soonbecomes exhausted → IPv6 (16-byte addresses).
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Address representation
IPv4: 32-bit (4-byte) addresses. Address space: 4,294,967,296. Soonbecomes exhausted → IPv6 (16-byte addresses).
• 207.142.131.235 dot-decimal
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Address representation
IPv4: 32-bit (4-byte) addresses. Address space: 4,294,967,296. Soonbecomes exhausted → IPv6 (16-byte addresses).
• 207.142.131.235 dot-decimal• 0xCF.0x8E.0x83.0xEB dotted-hexadecimal
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
IP addresses
• When connected, all network devices must have a unique IP.• IP address assignment is supervised by the Internet Assigned
Numbers Authority (IANA).• IANA delegates local registrations of IP addresses to Regional
Internet Registries (RIRs).
Address representation
IPv4: 32-bit (4-byte) addresses. Address space: 4,294,967,296. Soonbecomes exhausted → IPv6 (16-byte addresses).
• 207.142.131.235 dot-decimal• 0xCF.0x8E.0x83.0xEB dotted-hexadecimal• 0317.0216.0203.0353 dotted-octal
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Address allocation and ranges
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Address allocation and ranges
Routing
Selecting paths in a computer network along which to send dataaccording to the IP addresses found in the packet headers. It is afundamental principle of routing that the address encodes informationabout a device’s location within a network (like phone numbers, cf.area codes).
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Address allocation and ranges
Routing
Selecting paths in a computer network along which to send dataaccording to the IP addresses found in the packet headers. It is afundamental principle of routing that the address encodes informationabout a device’s location within a network (like phone numbers, cf.area codes).
Some reserved address ranges
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Address allocation and ranges
Routing
Selecting paths in a computer network along which to send dataaccording to the IP addresses found in the packet headers. It is afundamental principle of routing that the address encodes informationabout a device’s location within a network (like phone numbers, cf.area codes).
Some reserved address ranges
• private network (eg. 10.0.0.0 - 10.255.255.255 ): notroutable outside of the private network and private machinescannot directly communicate with public networks
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Address allocation and ranges
Routing
Selecting paths in a computer network along which to send dataaccording to the IP addresses found in the packet headers. It is afundamental principle of routing that the address encodes informationabout a device’s location within a network (like phone numbers, cf.area codes).
Some reserved address ranges
• private network (eg. 10.0.0.0 - 10.255.255.255 ): notroutable outside of the private network and private machinescannot directly communicate with public networks
• localhost (127.0.0.0 - 127.255.255.255 ): any addresswithin this range should never appear on an actual network andany packet sent to this address does not leave the sourcecomputer and will count as an incoming packet on that computer(loopback)
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Sample non-exam question
We . . .have now our own home LAN. What address range will we usefor our devices? (Well it’s easy to answer). And why?
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Name resolution
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Name resolution
157.181.67.129
This looks unfamiliar.
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Name resolution
157.181.67.129
This looks unfamiliar. How about this (albeit referring to thevery same network device, the SEAS server)?
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Name resolution
157.181.67.129
This looks unfamiliar. How about this (albeit referring to thevery same network device, the SEAS server)?
seas3.elte.hu
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Name resolution
157.181.67.129
This looks unfamiliar. How about this (albeit referring to thevery same network device, the SEAS server)?
seas3.elte.hu
“Dedicated network devices” are not normally publicly known byIP addresses but by names. This requires translating(resolving) names to IP addresses.
Kálmán, Oravecz, Szigetvári Networking
Network addressing IP addresses
Name resolution
157.181.67.129
This looks unfamiliar. How about this (albeit referring to thevery same network device, the SEAS server)?
seas3.elte.hu
“Dedicated network devices” are not normally publicly known byIP addresses but by names. This requires translating(resolving) names to IP addresses.
Domain Name System (DNS)
It translates domain names (computer hostnames) to IPaddresses.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• top-level domain
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• felso szintu domén
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• top-level domain• subdomains
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• top-level domain• aldomének
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• top-level domain• subdomains
• second-level domain
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• top-level domain• subdomains
• second-level domain• third level domain (a.k.a. host label)
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names
seas3.elte.hu
• top-level domain• subdomains
• second-level domain• third level domain (a.k.a. host label)
Top-level domains
• country code top-level domains (ccTLD)• generic top-level domains (gTLD)
• sponsored (.aero.coop.museum. . . )• unsponsored (.info.biz.com.edu.gov. . . )
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Homework
Home assigment
What is the IP address of www.example.com?
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain name assignment
ICANN (Internet Corporation for Assigned Names and Numbers)
Bears overall responsibility for managing the DNS. It controls the rootdomain, delegating control over each top-level domain to a domain nameregistry. For ccTLDs, the domain registry is typically controlled by thegovernment of that country. See www.domain.hu .
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain name assignment
ICANN (Internet Corporation for Assigned Names and Numbers)
Bears overall responsibility for managing the DNS. It controls the rootdomain, delegating control over each top-level domain to a domain nameregistry. For ccTLDs, the domain registry is typically controlled by thegovernment of that country. See www.domain.hu .
Cybersquatting
Registering or using a domain name with bad-faith intent to profit fromthe marketability of a trademark belonging to someone else.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain name assignment
ICANN (Internet Corporation for Assigned Names and Numbers)
Bears overall responsibility for managing the DNS. It controls the rootdomain, delegating control over each top-level domain to a domain nameregistry. For ccTLDs, the domain registry is typically controlled by thegovernment of that country. See www.domain.hu .
Cybersquatting
Registering or using a domain name with bad-faith intent to profit fromthe marketability of a trademark belonging to someone else.
Typosquatting
(a.k.a. URL hijacking) a form of cybersquatting which relies on mistakessuch as typographical errors made by Internet users when inputting awebsite address into a web browser.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain name assignment
ICANN (Internet Corporation for Assigned Names and Numbers)
Bears overall responsibility for managing the DNS. It controls the rootdomain, delegating control over each top-level domain to a domain nameregistry. For ccTLDs, the domain registry is typically controlled by thegovernment of that country. See www.domain.hu .
Cybersquatting
Registering or using a domain name with bad-faith intent to profit fromthe marketability of a trademark belonging to someone else.
Typosquatting
(a.k.a. URL hijacking) a form of cybersquatting which relies on mistakessuch as typographical errors made by Internet users when inputting awebsite address into a web browser.
Reverse domain hijacking
The practice of acquiring domain names from owners by accusing themof violating trademarks with the domain name, and demanding that thedomain be transferred.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
inter.net
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
inter.netdel.icio.us
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
inter.netdel.icio.uscr.yp.to
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
inter.netdel.icio.uscr.yp.toja.hu
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
inter.netdel.icio.uscr.yp.toja.husihu.hu
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Domain names extra
Unconventional domain names
Combines domain labels (especially the top level domain) to spell outa full user inviting name for a site.
inter.netdel.icio.uscr.yp.toja.husihu.hu
Resale of domain names
Huge market for generic names (dot-com era) that even withoutadvertising or marketing attract clients seeking services and productssimply typing in the generic name.business.com : sold for $7.5 million in 1999 (cf. the sex.com story).
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Homework
Home assigment
Collect three websites for which their common misspellingsredirect to the correct site, and three others which have somemisspelled URLs hijacked.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
RFC (Request for Comments)
A set of technical and organizational notes about the Internet. TheInternet Engineering Task Force (IETF) adopts some of the proposalspublished in RFCs as Internet standards (standards track RFCs).
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
RFC (Request for Comments)
A set of technical and organizational notes about the Internet. TheInternet Engineering Task Force (IETF) adopts some of the proposalspublished in RFCs as Internet standards (standards track RFCs).
DNS/Name server
The DNS consists of a hierarchical set of DNS servers. Each domainor subdomain has one or more authoritative DNS servers that publishinformation about that domain and the name servers of any domains"beneath" it.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
RFC (Request for Comments)
A set of technical and organizational notes about the Internet. TheInternet Engineering Task Force (IETF) adopts some of the proposalspublished in RFCs as Internet standards (standards track RFCs).
DNS/Name server
The DNS consists of a hierarchical set of DNS servers. Each domainor subdomain has one or more authoritative DNS servers that publishinformation about that domain and the name servers of any domains"beneath" it.
Fully qualified domain name (FQDN)
host label + domain = budling.nytud.hu
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Netmask (network mask, subnet mask)
Tells how many bits in IP address octet(s) identify thesubnetwork, and how many bits provide room for hostaddresses.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Netmask (network mask, subnet mask)
Tells how many bits in IP address octet(s) identify thesubnetwork, and how many bits provide room for hostaddresses.157.181.67.129 → 255.255.0.0
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Netmask (network mask, subnet mask)
Tells how many bits in IP address octet(s) identify thesubnetwork, and how many bits provide room for hostaddresses.157.181.67.129 → 255.255.0.0
192.168.2.101 → 255.255.255.0
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Netmask (network mask, subnet mask)
Tells how many bits in IP address octet(s) identify thesubnetwork, and how many bits provide room for hostaddresses.157.181.67.129 → 255.255.0.0
192.168.2.101 → 255.255.255.0This is information is for the router not for humans. When youhave to manually set it you will be provided with it or you canuse the default for your network.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway
General device to connect two distinct networks. (Our wifirouter is a type of gateway). When connecting two IP-basednetworks (like our home LAN with the ISP’s WAN):
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway
General device to connect two distinct networks. (Our wifirouter is a type of gateway). When connecting two IP-basednetworks (like our home LAN with the ISP’s WAN):→ two separate IP address, one on each network
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway
General device to connect two distinct networks. (Our wifirouter is a type of gateway). When connecting two IP-basednetworks (like our home LAN with the ISP’s WAN):→ two separate IP address, one on each network
• LAN address: the address to which traffic is sent from theLAN
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway
General device to connect two distinct networks. (Our wifirouter is a type of gateway). When connecting two IP-basednetworks (like our home LAN with the ISP’s WAN):→ two separate IP address, one on each network
• LAN address: the address to which traffic is sent from theLAN
• WAN address: the address to which traffic is sent comingfrom the WAN (for our home net it is assigned by the ISP)
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway
General device to connect two distinct networks. (Our wifirouter is a type of gateway). When connecting two IP-basednetworks (like our home LAN with the ISP’s WAN):→ two separate IP address, one on each network
• LAN address: the address to which traffic is sent from theLAN
• WAN address: the address to which traffic is sent comingfrom the WAN (for our home net it is assigned by the ISP)
→ gateway IP address: commonly the LAN address
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway — operation
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway — operation
• the addresses of computers on the LAN are hidden behindthe gateway
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway — operation
• the addresses of computers on the LAN are hidden behindthe gateway
• the WAN can only see the gateway’s IP address
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway — operation
• the addresses of computers on the LAN are hidden behindthe gateway
• the WAN can only see the gateway’s IP address• traffic regulation between the WAN and the LAN: Network
Address Translation (NAT)
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway — operation
• the addresses of computers on the LAN are hidden behindthe gateway
• the WAN can only see the gateway’s IP address• traffic regulation between the WAN and the LAN: Network
Address Translation (NAT)• all of the LAN traffic is presented to the WAN as coming
from the gateway’s WAN IP address
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts I.
Gateway — operation
• the addresses of computers on the LAN are hidden behindthe gateway
• the WAN can only see the gateway’s IP address• traffic regulation between the WAN and the LAN: Network
Address Translation (NAT)• all of the LAN traffic is presented to the WAN as coming
from the gateway’s WAN IP address• return WAN traffic is sorted and distributed to the local
network
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
The assignment of IP addresses
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
The assignment of IP addresses
Manual (static IP)
• IP address
• subnet mask
• default gateway
• DNS server(s)
must be specified.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
The assignment of IP addresses
Manual (static IP)
• IP address
• subnet mask
• default gateway
• DNS server(s)
must be specified.
Automatic (dynamic IP)
Dynamic Host Configuration Protocol (DHCP): used bynetworked computers (clients) to obtain unique IP addresses(and all other parameters) from a DHCP server.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts II.
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts II.
ServerA computer system that provides services to other computingsystems (clients) over a network. Server can refer to thehardware (heavy-duty irons with constrained user interface)and software (eg. RDBMS).
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Important concepts II.
ServerA computer system that provides services to other computingsystems (clients) over a network. Server can refer to thehardware (heavy-duty irons with constrained user interface)and software (eg. RDBMS).
Client
A computer system that accesses a (remote) service onanother computer by some kind of network. Also can refer tohardware (eg. PC) or software (like a web browser → universalclient).
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
✇ The device that connects two LANs together is a(n)A netmaskB IP addressC network fridgeD gateway
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
✇ The device that connects two LANs together is a(n)A netmaskB IP addressC network fridgeD gateway ✔
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
✇ The device that connects two LANs together is a(n)A netmaskB IP addressC network fridgeD gateway ✔
✇ The prebuilt unique identifier of a network device is itsA IP addressB MAC addressC wireless ethernet cardD topology
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
✇ The device that connects two LANs together is a(n)A netmaskB IP addressC network fridgeD gateway ✔
✇ The prebuilt unique identifier of a network device is itsA IP addressB MAC address ✔
C wireless ethernet cardD topology
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
✇ The device that connects two LANs together is a(n)A netmaskB IP addressC network fridgeD gateway ✔
✇ The prebuilt unique identifier of a network device is itsA IP addressB MAC address ✔
C wireless ethernet cardD topology
Audience questions
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Feedback slide I.
Sample exam questions
✇ The device that connects two LANs together is a(n)A netmaskB IP addressC network fridgeD gateway ✔
✇ The prebuilt unique identifier of a network device is itsA IP addressB MAC address ✔
C wireless ethernet cardD topology
Audience questions
• ???
Kálmán, Oravecz, Szigetvári Networking
Network addressing Domain names
Recap
• computer network
• (wireless) network interface
• MAC address
• modem, access point/router/gateway
• IP address
• domain names, name resolution, DNS• IP assignment:
• static: IP address, netmask, gateway address, DNS server• dynamic: DHCP (server)
• server, client
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Setting up a home LAN
?cable/ADSL modem
router(+switch)+Access
Point (AP)
����
Figure: This will hopefully be a working home LAN
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
LAN configuration
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
WAN configuration
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
WAN configuration
Point-to-Point Protocol over Ethernet• used mainly with ADSL services• offers features as authentication, encryption and compression• provides a classical connection with login and password
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
Wireless configuration — Set the Service Set Identifier
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
Wireless configuration — Set the Service Set Identifier
Secure the connection (by default it’s open!)
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
Tighten access to your AP
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Homework
Home assigment
What do the abbreviations WEP, WPA stand for?
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Router
We are up and running
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Clients
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Clients
• There must be some GUI for network configuration, depending onthe OS . . .
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Clients
• There must be some GUI for network configuration, depending onthe OS . . .
like this . . .
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Configuring the home LAN — Clients
• There must be some GUI for network configuration, depending onthe OS . . .
like this . . . or like this . . .
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
• uses the resources of the host computer (even the OS)
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
• uses the resources of the host computer (even the OS)
• usually only provides a GUI to a host server
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
• uses the resources of the host computer (even the OS)
• usually only provides a GUI to a host server
Fat client
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
• uses the resources of the host computer (even the OS)
• usually only provides a GUI to a host server
Fat client• does not necessarily rely on a server
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
• uses the resources of the host computer (even the OS)
• usually only provides a GUI to a host server
Fat client• does not necessarily rely on a server
• has local storage and its own OS
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Back to the university lab
Sitting in front of a thin client
• no local storage (diskless), minimal local processing
• uses the resources of the host computer (even the OS)
• usually only provides a GUI to a host server
Fat client• does not necessarily rely on a server
• has local storage and its own OS
• eg.: the PC
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Login windows
like this . . .
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
Login windows
like this . . . or like this . . .
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
User authentication
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
User authentication
• User/login name: from a limited set and number ofcharacters
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
User authentication
• User/login name: from a limited set and number ofcharacters
• Password: strong/weak (more on week 13)
Kálmán, Oravecz, Szigetvári Networking
Network addressing LAN configuration
User authentication
• User/login name: from a limited set and number ofcharacters
• Password: strong/weak (more on week 13)
When you log in to a diskless client all services/programs areprovided by a host server. In a fat client it may only be yourhome directory that is on a remote machine everything else islocal. Normally it is all hidden behind the user interface.
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet• worldwide, publicly accessible network
of interconnected computer networks. . .
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet• worldwide, publicly accessible network
of interconnected computer networks. . .
• using the standard Internet Protocol(IP), Transmission Control Protocol(TCP) and various applicationprotocols depending on the service(eg. DNS, HTTP, SMTP, POP3 etc.)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet• worldwide, publicly accessible network
of interconnected computer networks. . .
• using the standard Internet Protocol(IP), Transmission Control Protocol(TCP) and various applicationprotocols depending on the service(eg. DNS, HTTP, SMTP, POP3 etc.)
• provides many services: eg. DNS,electronic mail, file transfer, instantmessaging, streaming audio and video,online gaming and the World WideWeb
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet• worldwide, publicly accessible network
of interconnected computer networks. . .
• using the standard Internet Protocol(IP), Transmission Control Protocol(TCP) and various applicationprotocols depending on the service(eg. DNS, HTTP, SMTP, POP3 etc.)
• provides many services: eg. DNS,electronic mail, file transfer, instantmessaging, streaming audio and video,online gaming and the World WideWeb
World Wide Web• collection of
interconnecteddocuments, linked byhyperlinksa and URLs
aa reference or navigationelement in a document to anotherresource (document or part of)(week 11)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet• worldwide, publicly accessible network
of interconnected computer networks. . .
• using the standard Internet Protocol(IP), Transmission Control Protocol(TCP) and various applicationprotocols depending on the service(eg. DNS, HTTP, SMTP, POP3 etc.)
• provides many services: eg. DNS,electronic mail, file transfer, instantmessaging, streaming audio and video,online gaming and the World WideWeb
World Wide Web• collection of
interconnecteddocuments, linked byhyperlinksa and URLs
• most used and known(but just another)service of the Internet
aa reference or navigationelement in a document to anotherresource (document or part of)(week 11)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web
The Internet 6= World Wide Web
Internet• worldwide, publicly accessible network
of interconnected computer networks. . .
• using the standard Internet Protocol(IP), Transmission Control Protocol(TCP) and various applicationprotocols depending on the service(eg. DNS, HTTP, SMTP, POP3 etc.)
• provides many services: eg. DNS,electronic mail, file transfer, instantmessaging, streaming audio and video,online gaming and the World WideWeb
World Wide Web• collection of
interconnecteddocuments, linked byhyperlinksa and URLs
• most used and known(but just another)service of the Internet
• provides easy access toa vast and diverseamount of onlineinformation
aa reference or navigationelement in a document to anotherresource (document or part of)(week 11)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — Client-server architecture
Accessing a website
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — Client-server architecture
Accessing a website
• user types the URL (Uniform Resource Locator) of webpage into a web browser
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — Client-server architecture
Accessing a website
• user types the URL (Uniform Resource Locator) of webpage into a web browser
• hostname part of URL is resolved into a web server’s IPaddress
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — Client-server architecture
Accessing a website
• user types the URL (Uniform Resource Locator) of webpage into a web browser
• hostname part of URL is resolved into a web server’s IPaddress
• an HTTP (Hypertext Transfer Protocol) request is sent tothe web server at that IP address, for the page required
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — Client-server architecture
Accessing a website
• user types the URL (Uniform Resource Locator) of webpage into a web browser
• hostname part of URL is resolved into a web server’s IPaddress
• an HTTP (Hypertext Transfer Protocol) request is sent tothe web server at that IP address, for the page required
• server returns page (file(s)) which is rendered by the webbrowser on the client
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
The first web pages (1990)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Uniform Resource Identifier (URI)
Compact string of characters used to identify or name a resource.It enables interaction with or access to the resource over a network(typically the web) using specific protocols.
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Uniform Resource Identifier (URI)
Compact string of characters used to identify or name a resource.It enables interaction with or access to the resource over a network(typically the web) using specific protocols.
URI (in popular usage → URL) syntax
http︸︷︷︸
scheme
://example.com︸ ︷︷ ︸
host
:992︸︷︷︸
port
/animal/bird︸ ︷︷ ︸
path
?species=ferret︸ ︷︷ ︸
query
# wings︸ ︷︷ ︸
fragment
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Uniform Resource Identifier (URI)
Compact string of characters used to identify or name a resource.It enables interaction with or access to the resource over a network(typically the web) using specific protocols.
URI (in popular usage → URL) syntax
http︸︷︷︸
scheme
://example.com︸ ︷︷ ︸
host
:992︸︷︷︸
port
/animal/bird︸ ︷︷ ︸
path
?species=ferret︸ ︷︷ ︸
query
# wings︸ ︷︷ ︸
fragment
• mailto:cartman@southpark.org
• file:///usr/share/dict/words
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable• problem: there are far more Web sites than servers
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable• problem: there are far more Web sites than servers• in HTTP talk, the client tells the server which name is being used
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable• problem: there are far more Web sites than servers• in HTTP talk, the client tells the server which name is being used• one server with one IP address can provide different sites for
different domain names
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable• problem: there are far more Web sites than servers• in HTTP talk, the client tells the server which name is being used• one server with one IP address can provide different sites for
different domain names → virtual hosting
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable• problem: there are far more Web sites than servers• in HTTP talk, the client tells the server which name is being used• one server with one IP address can provide different sites for
different domain names → virtual hosting
telri.nytud.hu has address 193.6.194.149corpus.nytud.hu has address 193.6.194.149
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the server side
Virtual hosts• as a general rule, the IP address and the server name are
interchangeable• problem: there are far more Web sites than servers• in HTTP talk, the client tells the server which name is being used• one server with one IP address can provide different sites for
different domain names → virtual hosting
telri.nytud.hu has address 193.6.194.149corpus.nytud.hu has address 193.6.194.149
www is not mandatory in URLsindex.hu has address 217.20.131.2www.index.hu has address 217.20.131.2www.nytud.hu has address 193.6.194.40nytud.hu has address 193.6.194.1
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the client side
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the client side
Client software — popular browsers
• Mozilla Firefox (all platforms)• Opera (all platforms)• Internet Explorer (Windowses; no longer for Mac OS)• Safari (Mac OS)• lynx (poor man’s CLI browser)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the client side
Client software — popular browsers
• Mozilla Firefox (all platforms)• Opera (all platforms)• Internet Explorer (Windowses; no longer for Mac OS)• Safari (Mac OS)• lynx (poor man’s CLI browser)
Customizing your browser — Plugins and extensions
• plugin: application that interacts with the main program within awell defined framework to provide some specific functions
• in browsers: process specific types of files (eg. multimedia, pdf ✌)• in mailers: encrypt or decrypt email (week 13)• in graphic programs: filter and process certain images (week 12)
• extension: modifies or adds to existing functionality (Firefox ✌)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the client side
Customizing your browser — Proxies and other settings
• (caching) web proxy: a nearby cache of web pages andfiles available on remote web servers, allowing localnetwork clients to access them more efficiently, quickly orreliably
• cache: a place for temporary storage of data likely to beused again
• other important settings: security, local cache (IE!) etc.
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Operation — the client side
Figure: Setting a web proxy in Firefox
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Search engines
• programs designed to help efficiently find information stored on acomputer system (language technology may well come into playhere)
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Search engines
• programs designed to help efficiently find information stored on acomputer system (language technology may well come into playhere)
• operation:
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Search engines
• programs designed to help efficiently find information stored on acomputer system (language technology may well come into playhere)
• operation:• web crawling (spider)• indexing• searching: query → relevance ranked result set
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Search engines
• programs designed to help efficiently find information stored on acomputer system (language technology may well come into playhere)
• operation:• web crawling (spider)• indexing• searching: query → relevance ranked result set
• Examples:
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Search engines
• programs designed to help efficiently find information stored on acomputer system (language technology may well come into playhere)
• operation:• web crawling (spider)• indexing• searching: query → relevance ranked result set
• Examples:• http://www.webcrawler.com/ (the first, metasearch)• http://www.google.com/ (the most common)• http://search.yahoo.com/
Kálmán, Oravecz, Szigetvári Networking
The Internet and the World Wide Web The Web
Finding info on the Web
Web portals
An organized pathway to web content, providing various services(news, free email, customization features, chatrooms etc). For manyusers, the starting point of their web browser. (Examples?)
Search engines
• programs designed to help efficiently find information stored on acomputer system (language technology may well come into playhere)
• operation:• web crawling (spider)• indexing• searching: query → relevance ranked result set
• Examples:• http://www.webcrawler.com/ (the first, metasearch)• http://www.google.com/ (the most common)• http://search.yahoo.com/• countless others, even for specific purposes s.a. jobs, blogs,
business etc.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — Security
Warning
Whichever way you connect to a remote machine do it in asecure manner:
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — Security
Warning
Whichever way you connect to a remote machine do it in asecure manner:
• make sure sensitive information (eg. password) travelssecurely → use encrypted connection channels
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — Security
Warning
Whichever way you connect to a remote machine do it in asecure manner:
• make sure sensitive information (eg. password) travelssecurely → use encrypted connection channels
• all in all, try to avoid unsafe (open) protocols (telnet, FTP,HTTP for confidential web pages), and use SSH, SFTP,SCP, HTTPS instead
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Important concepts III.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Important concepts III.
(Software) Port
A virtual data connection that can be used by programs to exchangedata directly (instead of going through a file or other temporary storagelocation). Each data packet header contains a port number to mapdata to a particular process (program) running on a computer. Somecommon port numbers:
20 FTP data21 FTP command22 SSH (6= Social Sciences and Humanities)23 Telnet25 SMTP80 HTTP
110 POP3143 IMAP443 HTTPS993 IMAPS995 POP3S
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
✇ Which is the odd one out and why? (lead: hw/sw)A ClientB PortC GuiD Server
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
✇ Which is the odd one out and why? (lead: hw/sw)A ClientB PortC Gui ✔D Server
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
✇ Which is the odd one out and why? (lead: hw/sw)A ClientB PortC Gui ✔D Server
because . . .
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
✇ Which is the odd one out and why? (lead: hw/sw)A ClientB PortC Gui ✔D Server
because . . .
Audience questions
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
✇ Which is the odd one out and why? (lead: hw/sw)A ClientB PortC Gui ✔D Server
because . . .
Audience questions
• What the . . . is a LAN party?
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Feedback slide II.
Sample exam questions
✇ All in all, the Internet and the World Wide Web are synonymous.• True• False ✔
✇ Which is the odd one out and why? (lead: hw/sw)A ClientB PortC Gui ✔D Server
because . . .
Audience questions
• What the . . . is a LAN party?• Now it’s your turn . . .
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — GUIs
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — GUIs
Virtual Network Computing (VNC)
• a desktop sharing system to remotely control another computer• platform-independent: a VNC viewer on any OS can connect to a
VNC server on any other OS
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — GUIs
Virtual Network Computing (VNC)
• a desktop sharing system to remotely control another computer• platform-independent: a VNC viewer on any OS can connect to a
VNC server on any other OS
Remote Desktop Protocol
• allows a user to connect to a(Windows) computer runningMicrosoft Terminal Services
• still in development to enhance itsfunctionality
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — GUIs
X Server (Unices)
• allows a user to connect toa computer running an Xdisplay manager
• presents the user with alogin screen to insert theusername and password
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — GUIs
Figure: Schematics of a remote X connection
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — Poor man’s CLI
SSH connection — putty
• provides secure remote CLI connection in terminal window• can operate with the SSH (Secure Shell) protocol (please use
version 2!)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Remote login
Connecting to remote machines — Poor man’s CLI
SSH connection — putty
• provides secure remote CLI connection in terminal window• can operate with the SSH (Secure Shell) protocol (please use
version 2!)
Figure: Putty configuration
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines File transfer
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines File transfer
Transferring files the secure way
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines File transfer
Transferring files the secure way
SSH File Transfer Protocol (SFTP), Secure Copy Protocol (SCP)
• data is encrypted during transfer• SCP protocol implements file transfers only• SFTP protocol allows for a range of operations on remote files:
resuming interrupted transfers, directory listings, remote fileremoval
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines File transfer
Transferring files the secure way
SSH File Transfer Protocol (SFTP), Secure Copy Protocol (SCP)
• data is encrypted during transfer• SCP protocol implements file transfers only• SFTP protocol allows for a range of operations on remote files:
resuming interrupted transfers, directory listings, remote fileremoval
Clients: panel based (≈file manager) GUIs
• WinSCP (Windowses)• Fugu (Mac)• all builtin file managers of common desktop environments
(KDE, Gnome) (Linux)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines File transfer
Transferring files the secure way
Figure: WinSCP login window
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines File transfer
Transferring files the secure way
Figure: Remote directory listing in WinSCP
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➊ Alice composes amessage using her mailuser agent (MUA). Sends itto recipient’s address.MUA uses Simple MailTransfer Protocol (SMTP)to send message to localmail transfer agent (MTA)(smtp.a.org run by ISP).MTA looks up domainname from destinationaddress (b.org ) in DNS tofind mail exchange serversaccepting messages forthat domain.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➋-➌ DNS server (here for theb.org domain:ns.b.org ), responds withan MX (Mail eXchange)record listing the mailexchange servers for thatdomain (here mx.b.org , aserver run by Bob’s ISP)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➋-➌ DNS server (here for theb.org domain:ns.b.org ), responds withan MX (Mail eXchange)record listing the mailexchange servers for thatdomain (here mx.b.org , aserver run by Bob’s ISP)
☞ elte.hu mail ishandled by 10mx2.mail.elte.hu.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➋-➌ DNS server (here for theb.org domain:ns.b.org ), responds withan MX (Mail eXchange)record listing the mailexchange servers for thatdomain (here mx.b.org , aserver run by Bob’s ISP)
☞ elte.hu mail ishandled by 10mx2.mail.elte.hu.
☞ nytud.hu mail ishandled by 10genesis.nytud.hu.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➍ Alice’s MTA (smtp.a.org )sends the message toBob’s MX server(mx.b.org ) using SMTP,which delivers it to themailbox of the user bob .
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➍ Alice’s MTA (smtp.a.org )sends the message toBob’s MX server(mx.b.org ) using SMTP,which delivers it to themailbox of the user bob .
☞ telnetgenesis.nytud.hu 25. . .
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
telnet genesis.nytud.hu 25Trying 193.6.194.37...Connected to genesis.nytud.hu (193.6.194.37).Escape character is ’ˆ]’.220 genesis.nytud.hu ESMTP Sendmail 8.13.1/8.13.1;Sun, 15 Oct 2006 12:05:04 +0200HELO ny01.nytud.hu250 genesis.nytud.hu Hello ny01.nytud.hu[193.6.194.1], pleased to meet youMAIL FROM:<cartman@mit.edu>250 2.1.0 <cartman@mit.edu>... Sender okRCPT TO:<oravecz@nytud.hu>250 2.1.5 <oravecz@nytud.hu>... Recipient okDATA354 Enter mail, end with "." on a line by itselfFollow your dreams, You can reach your goals, I’mliving proof! Beefcake!.250 2.0.0 k9FA5491002427 Message accepted fordeliveryquit221 2.0.0 genesis.nytud.hu closing connectionConnection closed by foreign host.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➎ Bob presses the "get mail"button in his MUA, whichpicks up the messageusing the Post OfficeProtocol (POP3).
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the net
➎ Bob presses the "get mail"button in his MUA, whichpicks up the messageusing the Post OfficeProtocol (POP3).
☞ From cartman@mit.eduSun Oct 15 12:08:122006 . . .
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
How mail travels through the netFrom cartman@mit.edu Sun Oct 15 12:08:12 2006Return-Path: <cartman@mit.edu>Received: from genesis.nytud.hu (genesis.nytud.hu [193. 6.194.37])
by ny01.nytud.hu (8.11.6/8.11.6) with ESMTP id k9FA8A4178 59for <oravecz@nytud.hu>; Sun, 15 Oct 2006 12:08:10 +0200
Received: from ny01.nytud.hu (ny01.nytud.hu [193.6.194. 1])by genesis.nytud.hu (8.13.1/8.13.1) with SMTP id k9FA5491 002427for <oravecz@nytud.hu>; Sun, 15 Oct 2006 12:06:06 +0200
Date: Sun, 15 Oct 2006 12:05:04 +0200From: cartman@mit.eduMessage-Id: <200610151006.k9FA5491002427@genesis.nyt ud.hu>Content-Type: TEXT/PLAIN; charset=US-ASCIIX-AntiVirus: scanned for viruses by AMaViS 0.2.1 (http://a mavis.org/)X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on ny01.nytud.huX-Spam-Level:X-Spam-Status: No, hits=0.3 required=6.5 tests=NO_REAL_ NAME autolearn=no
version=2.63
Follow your dreams, You can reach your goals,I’m living proof! Beefcake!
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Internet e-mail format
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Internet e-mail format
Header
From: e-mail address (and name) of the senderTo: e-mail addresses (and names) of the receiver
Subject: brief summary lineDate: local time and date when message was originally sent
Cc: courtesy/carbon copyBcc: blind carbon copy; contains addresses of recipients of the
message whose addresses are not to be revealed to otherrecipients
Content-Type: information about how the message has to be displayed(MIMEa type)
aMultipurpose Internet Mail Extensions eg. Content-Type: image/gif;
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Internet e-mail format
Header
From: e-mail address (and name) of the senderTo: e-mail addresses (and names) of the receiver
Subject: brief summary lineDate: local time and date when message was originally sent
Cc: courtesy/carbon copyBcc: blind carbon copy; contains addresses of recipients of the
message whose addresses are not to be revealed to otherrecipients
Content-Type: information about how the message has to be displayed(MIMEa type)
aMultipurpose Internet Mail Extensions eg. Content-Type: image/gif;
Blank line
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Internet e-mail format
Header
From: e-mail address (and name) of the senderTo: e-mail addresses (and names) of the receiver
Subject: brief summary lineDate: local time and date when message was originally sent
Cc: courtesy/carbon copyBcc: blind carbon copy; contains addresses of recipients of the
message whose addresses are not to be revealed to otherrecipients
Content-Type: information about how the message has to be displayed(MIMEa type)
aMultipurpose Internet Mail Extensions eg. Content-Type: image/gif;
Blank line
Body: the message
• e-mail was originally designed for 7-bit ASCII• many mail transport agents still don’t support 8 bit transfer• content transfer encodings to encode 8 bit data for transmission:
quoted printable, base64 (handled by your MUA)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
An encoded binary attachment
------=_NextPart_000_00FE_01C65FE0.4FD94570Content-Type: application/msword;
name="hasznositasi_lehetosegek.doc"Content-Transfer-Encoding: base64Content-Disposition: attachment;
filename="hasznositasi_lehetosegek.doc"
0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAPgADAP7/CQAGAAAAAAAAAAAAAAABAAAAQgAAAAAAAAAAEAAARAAAAAEAAAD+////AAAAAEMAAAD//////////////////// //////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////// ////////////////////////s/////////////////////////////////////////////////// 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
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Variations on the mailing theme
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Variations on the mailing theme
Webmail instead of MUA✔ a web application that allow users to access their e-mail through a web
browser✔ accessible anywhere with an internet connection and a web browser✔ ensures a permanent address (change of ISP → end of mail service and
address at ISP!)✘ limited e-mail storage space, advertisements displayed• Hotmail, Yahoo!Mail, Gmail, Freemail etc. ✌
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Variations on the mailing theme
Webmail instead of MUA✔ a web application that allow users to access their e-mail through a web
browser✔ accessible anywhere with an internet connection and a web browser✔ ensures a permanent address (change of ISP → end of mail service and
address at ISP!)✘ limited e-mail storage space, advertisements displayed• Hotmail, Yahoo!Mail, Gmail, Freemail etc. ✌
Internet Message Access Protocol (IMAP) instead of POP3
Both allow a local client to access e-mail on a remote server. For and againstIMAP:
✔ both connected and disconnected modes of operation✔ multiple clients can simultaneously connect to the same mailbox✔ multiple mailboxes (folders) on the server✘ very complicated protocol (today no problem, so use this over POP3 if
possible)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Important concepts IV.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Important concepts IV.
Mailbox
The (local or remote) store of your messages. Standard types:
• maildir: a directory where each message is a separate file• mbox: a single file with all messages concatenated
➥ From cartman@mit.edu Sun Oct 15 12:08:12 2006
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Important concepts IV.
Mailbox
The (local or remote) store of your messages. Standard types:
• maildir: a directory where each message is a separate file• mbox: a single file with all messages concatenated
➥ From cartman@mit.edu Sun Oct 15 12:08:12 2006
Folder
A mailbox (file) for specific types of messages. Standard types offeredby most MUAs include:
• Inbox: default place for incoming messages• Sent: for a copy of messages you send• Drafts: placeholder for messages under composition• Trash: backup folder for deleted messages
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
MUAs and their basic commands
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
MUAs and their basic commands
Popular graphical MUAs
• Mozilla Thunderbird (all platforms)
• Tiger Mail (Mac)
• Outlook Express (Windowses, Mac) . . . and countlessothers
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
MUAs and their basic commands
Popular graphical MUAs
• Mozilla Thunderbird (all platforms)
• Tiger Mail (Mac)
• Outlook Express (Windowses, Mac) . . . and countlessothers
Basic commands• get mail
• write/compose (→ attach)
• send
• reply (all)
• forward, bounce
• delete ✌
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Setting up a MUA for remote mail service
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Setting up a MUA for remote mail service
General account settings Mail server settings
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Local MUAs on servers with own MTA
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Local MUAs on servers with own MTA
Local access to mailboxes• normally for users of servers with unrestricted access• possible with GUI MUAs but the typical scenario is to log in
to a server through a CLI and starting some CLI mail client• pine• mutt• elm
• some of them are very powerful (pine, mutt) and offermuch the same functionality as GUI MUAs
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Humble CLI mail client
Mailbox is ’/var/spool/mail/oravecz’ with 1858 messages [ ELM 2.5 PL6]
N 1 Oct 15 *** / cartman@mit.edu (19)NM 3 Oct 15 (Undisclosed) nyelveszForumAdmin (65) Téma érte sítésO 175 Jul 29 Corpora / John F. Sowa (98) Re: [Corpora-List] ANCO 176 Jul 29 Corpora / Nicholas Sanders (82) Re: [Corpora-Lis t] ANCO 177 Jul 28 Corpora / John F. Sowa (84) Re: [Corpora-List] ANCO 178 Jul 28 Corpora / Nicholas Sanders (77) [Corpora-List] R e: ANCO 179 Jul 28 Corpora / Nicholas Sanders (77) Re: [Corpora-Lis t] ANCO 180 Jul 28 Corpora / FIDELHOLTZ_DOOCHIN (85) [Corpora-Lis t] Re: ANC
|=pipe, !=shell, ?=help, <n>=set current to n, /=search pat terna)lias, C)opy, c)hange folder, d)elete, e)dit, f)orward, g )roup reply, m)ail,
n)ext, o)ptions, p)rint, q)uit, r)eply, s)ave, t)ag, u)nde lete, or e(x)it
Command:
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
• sorting messages into different folders
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
• sorting messages into different folders• forwarding messages
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
• sorting messages into different folders• forwarding messages• labeling messages
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
• sorting messages into different folders• forwarding messages• labeling messages• deleting messages etc.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
• sorting messages into different folders• forwarding messages• labeling messages• deleting messages etc.
with the help of filter rules that match on sections ofmessage header.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — MDAs
Mail Delivery Agent (MDA)
• program that accepts incoming e-mail messages andperforms certain actions over them like
• sorting messages into different folders• forwarding messages• labeling messages• deleting messages etc.
with the help of filter rules that match on sections ofmessage header.
• most GUI MUAs have this as built in functionality ✌
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
• ask the system administrator to trap it at the mail serverlevel
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
• ask the system administrator to trap it at the mail serverlevel
• don’t publish your e-mail address at open websites withnormal syntax (use address munging)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
• ask the system administrator to trap it at the mail serverlevel
• don’t publish your e-mail address at open websites withnormal syntax (use address munging)cartman@mit.edu
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
• ask the system administrator to trap it at the mail serverlevel
• don’t publish your e-mail address at open websites withnormal syntax (use address munging)cartman@mit.edu ✘
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
• ask the system administrator to trap it at the mail serverlevel
• don’t publish your e-mail address at open websites withnormal syntax (use address munging)cartman@mit.edu ✘
cartman-kukac-mit-edu
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing
Filtering incoming mail — spams
Spam
Unsolicited messages to many recipients, the electronicequivalent of junk mail (week 13). To avoid:
• use some automated e-mail filtering program
• ask the system administrator to trap it at the mail serverlevel
• don’t publish your e-mail address at open websites withnormal syntax (use address munging)cartman@mit.edu ✘
cartman-kukac-mit-edu ✔
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses• reflector: a single e-mail address that sends a copy of the
message to all of the subscribers
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses• reflector: a single e-mail address that sends a copy of the
message to all of the subscribers• server/program operated service; additional e-mail addresses
for administration
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses• reflector: a single e-mail address that sends a copy of the
message to all of the subscribers• server/program operated service; additional e-mail addresses
for administration
Types
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses• reflector: a single e-mail address that sends a copy of the
message to all of the subscribers• server/program operated service; additional e-mail addresses
for administration
Types
• announcement list: one-way information; can only be postedto by selected people
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses• reflector: a single e-mail address that sends a copy of the
message to all of the subscribers• server/program operated service; additional e-mail addresses
for administration
Types
• announcement list: one-way information; can only be postedto by selected people
• discussion list: any subscriber may post
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Mailing lists
• a list of e-mail addresses• subscribers receiving mail at those addresses• reflector: a single e-mail address that sends a copy of the
message to all of the subscribers• server/program operated service; additional e-mail addresses
for administration
Types
• announcement list: one-way information; can only be postedto by selected people
• discussion list: any subscriber may post• moderated list: every message must be approved by a
moderator
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
• arranged into (dot.sep.a.rated ) hierarchies to find relatedgroups easily
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
• arranged into (dot.sep.a.rated ) hierarchies to find relatedgroups easily
• distributed by dedicated news servers using the NetworkNews Transfer Protocol (NNTP – port 119)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
• arranged into (dot.sep.a.rated ) hierarchies to find relatedgroups easily
• distributed by dedicated news servers using the NetworkNews Transfer Protocol (NNTP – port 119)
Usenet (USEr NETwork)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
• arranged into (dot.sep.a.rated ) hierarchies to find relatedgroups easily
• distributed by dedicated news servers using the NetworkNews Transfer Protocol (NNTP – port 119)
Usenet (USEr NETwork)
• a global, distributed Internet discussion system
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
• arranged into (dot.sep.a.rated ) hierarchies to find relatedgroups easily
• distributed by dedicated news servers using the NetworkNews Transfer Protocol (NNTP – port 119)
Usenet (USEr NETwork)
• a global, distributed Internet discussion system• worldwide newsgroups are organized within nine hierarchies,
eight of which work under consensual guidelines aboutadministration and naming
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Mailing lists, newsgroups and discussion forums
Newsgroups
• a repository for a discussion group (orginally within the Usenetsystem) for messages posted from many users
• arranged into (dot.sep.a.rated ) hierarchies to find relatedgroups easily
• distributed by dedicated news servers using the NetworkNews Transfer Protocol (NNTP – port 119)
Usenet (USEr NETwork)
• a global, distributed Internet discussion system• worldwide newsgroups are organized within nine hierarchies,
eight of which work under consensual guidelines aboutadministration and naming
• creation of a new newsgroup under the Big 8 is a Big-8Management Board controlled procedure
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
The Big 8
comp. * computer-related discussionsmisc. * Miscellaneous topicsnews. * Discussions and announcements about Usenetrec. * Recreation and entertainmentsci. * Science related discussionssoc. * Social discussionstalk. * Talk about various topicshumanities. * Fine arts, literature, philosophy
Table: The Big 8 top hierarchies
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
The Big 8
comp. * computer-related discussionsmisc. * Miscellaneous topicsnews. * Discussions and announcements about Usenetrec. * Recreation and entertainmentsci. * Science related discussionssoc. * Social discussionstalk. * Talk about various topicshumanities. * Fine arts, literature, philosophy
Table: The Big 8 top hierarchies
• alt.*: the big 9th but not controlled
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
The Big 8
comp. * computer-related discussionsmisc. * Miscellaneous topicsnews. * Discussions and announcements about Usenetrec. * Recreation and entertainmentsci. * Science related discussionssoc. * Social discussionstalk. * Talk about various topicshumanities. * Fine arts, literature, philosophy
Table: The Big 8 top hierarchies
• alt.*: the big 9th but not controlled• other hierarchies (regional, language-specific), local news
service ✌
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
• essentially a website composed of a number ofmember-written threads
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
• essentially a website composed of a number ofmember-written threads
• user, registration, moderator, administrator
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
• essentially a website composed of a number ofmember-written threads
• user, registration, moderator, administrator
• wide range of topics
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
• essentially a website composed of a number ofmember-written threads
• user, registration, moderator, administrator
• wide range of topics
• allows anyone to reply to an existing or create a new thread
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
• essentially a website composed of a number ofmember-written threads
• user, registration, moderator, administrator
• wide range of topics
• allows anyone to reply to an existing or create a new thread
• e-mail notification
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Mailing list, newsgroups, forums
Discussion forums
Internet forum• a WWW facility for holding discussions
• also the software providing the facility
• essentially a website composed of a number ofmember-written threads
• user, registration, moderator, administrator
• wide range of topics
• allows anyone to reply to an existing or create a new thread
• e-mail notification
• good place to find an answer to very obscure questionssuch as how to fix a particular computer problem
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Instant messaging
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Instant messaging
• real-time communication between two or more peoplebased on typed text
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Instant messaging
• real-time communication between two or more peoplebased on typed text
• requires the use of a client program that connects to aninstant messaging service
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Instant messaging
• real-time communication between two or more peoplebased on typed text
• requires the use of a client program that connects to aninstant messaging service
• contact list: people currently online and available to chat
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Instant messaging
• real-time communication between two or more peoplebased on typed text
• requires the use of a client program that connects to aninstant messaging service
• contact list: people currently online and available to chat
• status message: ≈ message on a telephone answeringmachine
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Instant messaging
• real-time communication between two or more peoplebased on typed text
• requires the use of a client program that connects to aninstant messaging service
• contact list: people currently online and available to chat
• status message: ≈ message on a telephone answeringmachine
• .NET Messenger Service, AOL Instant Messenger, GoogleTalk, iChat, ICQ, Jabber, Qnext, QQ, Skype, Yahoo!Messenger, talk
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
• private messaging is also allowed
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
• private messaging is also allowed• client-server; Xchat, Bersirc, ChatZilla, Opera
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
• private messaging is also allowed• client-server; Xchat, Bersirc, ChatZilla, Opera• channel/user modes: moderated; i nvisible etc.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
• private messaging is also allowed• client-server; Xchat, Bersirc, ChatZilla, Opera• channel/user modes: moderated; i nvisible etc.• IRC bot: a program that connects as a client and performs
special services (managing channels, logging, giving outinformation on demand, creating statistics etc.)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
• private messaging is also allowed• client-server; Xchat, Bersirc, ChatZilla, Opera• channel/user modes: moderated; i nvisible etc.• IRC bot: a program that connects as a client and performs
special services (managing channels, logging, giving outinformation on demand, creating statistics etc.)
• 2D visual chat rooms: a graphic representation of the user(avatar) movable around a graphic background of the room
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Real time communication
Chat rooms• Internet Relay Chat (IRC)
• text based group (many-to-many) communication indiscussion channels
• private messaging is also allowed• client-server; Xchat, Bersirc, ChatZilla, Opera• channel/user modes: moderated; i nvisible etc.• IRC bot: a program that connects as a client and performs
special services (managing channels, logging, giving outinformation on demand, creating statistics etc.)
• 2D visual chat rooms: a graphic representation of the user(avatar) movable around a graphic background of the room
• 3D chat rooms utilize 3D graphics, allow users to build theirown spaces
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
• can be written by one person or a group of contributors
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
• can be written by one person or a group of contributors
Wiki wiki
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
• can be written by one person or a group of contributors
Wiki wiki• online collaboration model and tool that allows any user to
edit some content of webpages through a simple browser
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
• can be written by one person or a group of contributors
Wiki wiki• online collaboration model and tool that allows any user to
edit some content of webpages through a simple browser
• does not require users to know HTML (week 11) but writtenin a simple markup language
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
• can be written by one person or a group of contributors
Wiki wiki• online collaboration model and tool that allows any user to
edit some content of webpages through a simple browser
• does not require users to know HTML (week 11) but writtenin a simple markup language
• wikitext: source format
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Blogs and Wikis
Web log
• online journal evolved from online diary
• frequent, chronological publication of personal thoughts
• can be written by one person or a group of contributors
Wiki wiki• online collaboration model and tool that allows any user to
edit some content of webpages through a simple browser
• does not require users to know HTML (week 11) but writtenin a simple markup language
• wikitext: source format
Learn them by use.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
✇ A primary difference between forums and mailing lists is thatA the former operates over the Internet while the latter is localB the latter automatically delivers new messages to subscribers while
the former normally requires the user to check for thisC the former might be moderated, the latter neverD the latter is operated by a dedicated program, the former is
operated by a web browser
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
✇ A primary difference between forums and mailing lists is thatA the former operates over the Internet while the latter is localB the latter automatically delivers new messages to subscribers while
the former normally requires the user to check for this ✔
C the former might be moderated, the latter neverD the latter is operated by a dedicated program, the former is
operated by a web browser
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
✇ A primary difference between forums and mailing lists is thatA the former operates over the Internet while the latter is localB the latter automatically delivers new messages to subscribers while
the former normally requires the user to check for this ✔
C the former might be moderated, the latter neverD the latter is operated by a dedicated program, the former is
operated by a web browser✇ The standard client to read newsgroup posts is the Firefox web
browser.• True• False
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
✇ A primary difference between forums and mailing lists is thatA the former operates over the Internet while the latter is localB the latter automatically delivers new messages to subscribers while
the former normally requires the user to check for this ✔
C the former might be moderated, the latter neverD the latter is operated by a dedicated program, the former is
operated by a web browser✇ The standard client to read newsgroup posts is the Firefox web
browser.• True• False ✔
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
✇ A primary difference between forums and mailing lists is thatA the former operates over the Internet while the latter is localB the latter automatically delivers new messages to subscribers while
the former normally requires the user to check for this ✔
C the former might be moderated, the latter neverD the latter is operated by a dedicated program, the former is
operated by a web browser✇ The standard client to read newsgroup posts is the Firefox web
browser.• True• False ✔
Audience questions
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Other social netfacilities
Feedback slide III.
Sample exam questions
✇ A primary difference between forums and mailing lists is thatA the former operates over the Internet while the latter is localB the latter automatically delivers new messages to subscribers while
the former normally requires the user to check for this ✔
C the former might be moderated, the latter neverD the latter is operated by a dedicated program, the former is
operated by a web browser✇ The standard client to read newsgroup posts is the Firefox web
browser.• True• False ✔
Audience questions
• ???
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Outline1 Introduction
Sample exam question2 Computer networking
Sharing informationNetwork types and topologies
3 Back to the hardwareNetwork devices
4 Network addressingIP addressesDomain namesLAN configuration
5 The Internet and the World Wide WebThe Web
6 Connecting to remote machinesRemote loginFile transferMailingMailing list, newsgroups, forumsOther social netfacilitiesNetiquette
7 History
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:• think before you post
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:• think before you post• quote interspersed, with your response following the relevant
quoted material (and only the relelvant!)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:• think before you post• quote interspersed, with your response following the relevant
quoted material (and only the relelvant!)• to express irony, sarcasm etc. use but do not overuse
emoticons
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:• think before you post• quote interspersed, with your response following the relevant
quoted material (and only the relelvant!)• to express irony, sarcasm etc. use but do not overuse
emoticons• post in plain text
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:• think before you post• quote interspersed, with your response following the relevant
quoted material (and only the relelvant!)• to express irony, sarcasm etc. use but do not overuse
emoticons• post in plain text• before asking a question, read the messages already in the
group and read the group’s FAQ
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Conventions of politeness recognized on Usenet, in mailing lists,and on other electronic forums.
Newsgroups:• think before you post• quote interspersed, with your response following the relevant
quoted material (and only the relelvant!)• to express irony, sarcasm etc. use but do not overuse
emoticons• post in plain text• before asking a question, read the messages already in the
group and read the group’s FAQ• keep flames under control, don’t be a troll or off-topic
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists• follow standard grammar/spelling rules and don’t use slang
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists• follow standard grammar/spelling rules and don’t use slang• post in the correct forum category
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists• follow standard grammar/spelling rules and don’t use slang• post in the correct forum category• don’t double post
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists• follow standard grammar/spelling rules and don’t use slang• post in the correct forum category• don’t double post
Recommended practice is . . .
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists• follow standard grammar/spelling rules and don’t use slang• post in the correct forum category• don’t double post
Recommended practice is . . .• to read RFC 1855 (Netiquette Guidelines)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Netiquette
Internet etiquette
Forums:• read any rules and guidelines established by the community• before creating a new topic thread, search to see if a similar
topic already exists• follow standard grammar/spelling rules and don’t use slang• post in the correct forum category• don’t double post
Recommended practice is . . .• to read RFC 1855 (Netiquette Guidelines)• to educate yourself in the matter (GIYF)
Kálmán, Oravecz, Szigetvári Networking
Connecting to remote machines Netiquette
Homework
Home assigment
What do the abbreviations EOD, FGI, FYI, GIYF, GLOG, RTFM,UTFW stand for? Do some backround research on Internetslang.
Kálmán, Oravecz, Szigetvári Networking
History
Homework
Home assigment
Do some background reading on the history of the Internet (cf.ARPANET) and the Web.
Kálmán, Oravecz, Szigetvári Networking
top related