1 internet internet 52807 e-mail : claven@cc.nctu.edu.tw consult@cc.nctu.edu.tw 52807 e-mail :...

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InterNet InterNet 簡介簡介

主講人：柯皓仁國立交通大學計算機中心

分機： 52807

E-mail : claven@cc.nctu.edu.tw

問題諮詢： consult@cc.nctu.edu.tw

主講人：柯皓仁國立交通大學計算機中心

分機： 52807

E-mail : claven@cc.nctu.edu.tw

問題諮詢： consult@cc.nctu.edu.tw

2 時程表時程表Introduction To InternetDomain Name & Internet AddressThe Basic Services of InternetYour First Steps on InternetAdvanced Services of Internet

Introduction To InternetDomain Name & Internet AddressThe Basic Services of InternetYour First Steps on InternetAdvanced Services of Internet

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Introduction to InternetIntroduction to Internet

What is a network?What is InternetA Brief History of Internet

What is a network?What is InternetA Brief History of Internet

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What is The Internet?What is The Internet?

A network of networksA large collection of independent networks, all

of which run TCP/IP, that are tied together.

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The InternetThe Internet

NSFNET

Other NETS

APARNET

MILNET

TANET

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What can Internet Do for Users?What can Internet Do for Users?Communication

Electronic MailI-Phone

Learning and Discussing toolBBSUsenet

Collecting informationLibrary Searching

EntertainmentMUD

CommercialOn-Line Order

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Domain Name & IP AddressDomain Name & IP Address

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IP AddressIP AddressA way to identify uniquelyuniquely an area of the Net or an c

omputer on the NetConsists of 4 digits, each of which ranges from

0 to 255 (usually 1-254), separated by dot(.)140.113.1.1

140 : Taiwan113 : NCTU

If you want to connect your computer to Inter-net, aask your network manager for an IP addresssk your network manager for an IP address

13 Domain Name System (DNS)Domain Name System (DNS)

Internet

TW

EDU

NCTU CC CCSUN1

140.113.4.11 --> ccsun1.cc.nctu.edu.tw140.113.4.11 --> ccsun1.cc.nctu.edu.tw

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Domain Name System(DNS)Domain Name System(DNS)

A symbolic name for an IP-address (machine)A domain: an organization level within InternetDomains can be connected together (by dot (.)) to

create a unique identifier.left to right: most specific to most general Top-level : organizational or geographicask your network manager for your domain ask your network manager for your domain

Name(FQDN, Full Qualified Domain Name)Name(FQDN, Full Qualified Domain Name)

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Top Organization DomainsTop Organization Domains

Domain Purposecom Commercial Entitesedu Educational Institutionsgov non-military US Government Institutionorg Non-profit Organizationsnet Network Resourcesmil US military Institutionsint International Institutions (NATO)

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Top Geographic DomainsTop Geographic Domains

Domain Countrytw Taiwanjp Japande Germanyfr Franceus United Statesuk United Kingdomca Canada

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TANet DomainTANet Domain

tw edu.tw

org.tw

nctu.edu.twnthu.edu.tw

ntu.edu.tw

cc.nctu.edu.twcis.nctu.edu.twcsie.nctu.edu.tw

..... .....

com.tw

gov.tw

net.tw

18 Hostname VS DomainnameHostname VS Domainname

TW

EDU

NCTU CC CCSUN1

140.113.4.11 --> ccsun1.cc.nctu.edu.tw140.113.4.11 --> ccsun1.cc.nctu.edu.tw

ccsun1 is the hostname of 140.113.4.1 ccsun1.cc.nctu.edu.tw is the domainname(FQDN) of 140

.113.4.1When you connect to a machine within the same domain

, you can just use that machine's hostname

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TThe Basic Service of Internethe Basic Service of Internet

Virtual Terminal Service (telnet)File Transfer Service (ftp)E-Mail Service (SMTP)

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Virtual Terminal Service (telnet)Virtual Terminal Service (telnet)

$telnet hostTrying...Connected to hostEscape Character is '^]'

host's O.S. Version(host) login: <--- UserNamepasswd: <--- Password$ ........................................................$logoutConnection closed by foreign host.

...............................................

Work as if you are on host

Use Resources and Services of host

Come back to Local

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File Transfer Service (ftp)File Transfer Service (ftp)$ftp hostConnected to host. 220 host FTP server readyName(host:username): Password:User username logged in.ftp>

ftp> quit (Come back to the local)

OK. Connect to FTP Server.You can get or put files now.

Enter your username/password

22 FFile Transfer Service (ftp) (Cont.)ile Transfer Service (ftp) (Cont.)Use get command to copy file(s) from the remo

te host.ftp> get <remote_file>

Use put command to copy local file(s) to theremote host.ftp> put <local_file>

You can use cd, ls,....,etc. as in UNIX Use ? in the 'ftp>' prompt to get helpYou should be a user of the remote host to get

/put files

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Anonymous FTPAnonymous FTP

Some hosts on Internet are set up in a way thatyou can use file transfer service to get publicdomain utilities without an account on it.

$ftp hostConnected to host. 220 host FTP server readyName(host:username): anonymous/ftpanonymous/ftpPassword:claven@cc.nctu.edu.tw (E-mail)claven@cc.nctu.edu.tw (E-mail)ftp>

Do as normal ftp

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FTP ExerciseFTP Exercise Anonymous FTP between PC and a server

d:\> ftp nctuccca.nctu.edu.twftp nctuccca.nctu.edu.twlogin: ftpftppassword: claven@cc.nctu.edu.twclaven@cc.nctu.edu.twftp> pwdpwdftp> binarybinaryftp> cd /NCTU/SLIP-Servicecd /NCTU/SLIP-Serviceftp> lslsftp> get slippr13.zipget slippr13.zipftp> quitquit

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FTP Exercise (Cont.)FTP Exercise (Cont.) Transfer files by your account

d:\> ftp ccsunxxftp ccsunxxlogin: YOUR USERNAMEYOUR USERNAME

password: YOUR PASSWORDYOUR PASSWORDftp> lcd d:\lcd d:\ftp>? lcd? lcdftp> asciiasciiftp>? ascii? asciiftp> get .cshrc cshrc.nodget .cshrc cshrc.nodftp> quitquit

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EElectronic Mail (SMTP)lectronic Mail (SMTP)

You can use Mail (BSD), mailx(SV), or elm tosend your electronic letter to a remote user.

Mail user@host < letter.txtYou send a file named letter.txt created in advance.host should be a domain name unless you and the user are

within the same domain.

Mail user@hostEnter your Subject and your message, and press

CTRL-D to complete the input of your message.

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Your First Steps on InternetYour First Steps on Internet

How to display the status of machinesHow to check if a host is currently AvailableHow to list the users logged on to a systemHow to talk to other users

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Using the rup commandUsing the rup command

The function of the rup command:Display the status of the machines within the same su

bnet

ruprup <hostname>

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Using the ping CommandUsing the ping Command

The function of the ping commandTell you if a remote computer is currently available o

n the network.

ping <domainname> : Display a short messageping -s <domainname> : Also show the perfor

mance of the link between you and the remote host Use Ctrl-C to end the ping -s command.

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Using the rusers/ku CommandUsing the rusers/ku Command

Use rusers/ku to display the users logged into the systems within the same subnet.

rusersrusers <hostname>

31 Using the talk commandUsing the talk commandThe function of the talk command:

Let you make a on-line conversation with other userstalk <username>@<domainname>

Use Ctrl-C to terminate conversation.Using the mesg

mesg y : allow the talk requestmesg n : reject the talk requestmesg : display the current mesg setup

Other version of talk:ctalk : Can use Chineseytalk : Can talk with users on the systems not using UN

IXcytalk: Can use Chinese

32 EExample of talkxample of talk

Message from Talk_Daemon@ccsun2 at 16:00talk: connection requested by jami@ccsun2talk: respond with: talk jami@ccsun2

The message shown on my screen

Jami on ccsun2 want to talk with freddyStep1: Use rusers to find if freddy is logged ont

osome sysytem.

Step2: Ah, freddy is on ccsun1Step3: talk freddy@ccsun1

freddy can issue talk jami@ccsun2 to beginthe on-line conversation with jami

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AAdvanced Services of Internetdvanced Services of Internet

Usenet NewsGopherBBSWWW

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UUsenet Newssenet NewsA collection of discussion groups that serves as

a giant bulletin board.You can obtain the information you want from News.You can post a questions to the News and get your

answer.You can respond your opinion on some topic or

answer the question asked by others.

Use the tin command to read Usenet NewsAs a novice user, Please use your eyes more Please use your eyes more

than your fingersthan your fingers.

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GopherGopher

Gopher is an information retrieval system that let you search information from all around the world.

Use the gopher command to enter the gopher system

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BBS (Bulletin Board System)BBS (Bulletin Board System)

Integrate a few of network services as a whole system.Post and read of bulletin board (similar to news)Electronic MailTalkRetrieve files....

Use telnet <BBS-Server> and follow the direction to enter BBS

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WWW (World-Wide Web)WWW (World-Wide Web)

WWW is a multi-media, hyper-text information providing system.

On PC Windows 95/NTUse netscape or mosaic to browse WWW

On Workstation X-windows ScreenUse netscape or mosaic to browse WWW