define dns1

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Define DNS

The DNS translates Internet domain and host names to IP addresses. DNS automatically converts the names we type in our Web browser address bar to the IP

addresses of Web servers hosting those sites. DNS implements a distributed database to store this name and address information for all public hosts on the

Internet.

Define Telnet

Telnet is the main Internet protocol for creating a connection to a remote server.

Define SMTP.

SMTP - Short for Simple Mail Transfer Protocol, a protocol for sending e-mail messages between servers.

What Is a MAC Address?

MAC (Media Access Control) addresses are globally unique addressed that are written into hardware at the time of manufacture. The MAC address is a unique

value associated with a network adapter. MAC addresses are also known as hardware addresses or physical addresses. They uniquely identify an adapter on a

LAN. MAC addresses are 12-digit hexadecimal numbers (48 bits in length).

Explain IP, TCP and UDP.

TCP Transmission control Protocol is used to establish communication between nodes or networks and exchange data packets. It guarantees delivery of data

packets in the order they were sent. Hence it is most commonly used in all applications that require guaranteed delivery of data. It can handle both timeouts (if

packets were delayed) and retransmission (if packets were lost). The stream of data is transmitted in segments. The segment header is 32 bit. it is a

connectionless communication protocol at the third level (network) of the OSI model.

IP Internet protocol is used for transmission of data over the internet. IP uses IP addresses to identity each machine uniquely. Message is sent using small

packets. The packet contains both the sender and receivers address. IP does not guarantee the delivery in the same order as sent. This is because the packets

are sent via different routes. It is a connectionless communication protocol at the third level (network) of the OSI model.

UDP User Data Protocol is a communication protocol. It is normally used as an alternative for TCP/IP. However there are a number of differences between them.

UDP does not divide data into packets. Also, UDP does not send data packets in sequence. Hence, the application program must ensure the sequencing. UDP

uses port numbers to distinguish user requests. It also has a checksum capability to verify the data.


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How would you define IP address?

IP address or Internet Protocol address is the address of a device attached to an IP network (TCP/IP network). It is a must for every client, server and network

device to have a unique IP address for each network connection (network interface). Every IP packet contains a source IP address and a destination IP address.

As a device moves from one network to another, its IP address changes.

Explain the core naming mechanism, Domain Name System (DNS).

A Domain Name system is used to convert the names of the website on the internet to IP addresses. The domain names for each IP addresses are stored in a

database that is distributed across different servers. A domain name space consists of a tree of domain names. The tree has zones. Zones consist of a collection

of connected nodes. These nodes are served by a name server. A domain name is usually in the form of mydomain.com. Here, .com is the top level domain.

Where as mydomain is the sub domain or subdivision. A host name is a domain name that has one or more IP addresses associated with it.

Define Spanning-Tree Protocol (STP)

Spanning-Tree Protocol (STP) as defined in the IEEE 802.1D is a link management protocol that provides path redundancy while preventing undesirable loops in

the network. For an Ethernet network to function properly, only one active path can exist between two stations. Loops occur in networks for a variety of reasons.

The most common reason you find loops in networks is the result of a deliberate attempt to provide redundancy - in case one link or switch fails, another link or

switch can take ove

What is VPN?

A VPN is a service that offers secure, reliable connectivity over a shared public network infrastructure such as the Internet. VPNs maintain the same security and

management policies as a private network. They are the most cost effective method of establishing a virtual point-to-point connection between remote users and

an enterprise customer's network.

What is VPN?

Virtual Private network is a network that used the public telecommunication infrastructure. This means that it used public wires to connect the nodes. E.g. Internet.

VPN supports remote access to computers and allow data to be transmitted over this public network. Even though the data is transmitted over a public network,

encryption and decrypting data to ensure security.


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What is the difference between public and private IP?

A public IP address allows equipment accessible to everyone on the internet. A private IP address is for private use within the network and allows many more PCs

to be connected. If you are using a private IP and wants VOIP, you need to change to a public IP address.

Explain Maximum Transfer Unit, MTU.

MTU specifies the largest amount of data that can be transferred across a network.

Define broadcast domain.

It is a logical area in a computer network where any computer connected to the network can directly transmit to any other computer in the domain without having to

go through a routing device.

Bridge vs switch

A bridge connects two different LAN networks. A switch is something like you can connect many computers to a switch and then one computer can connect to

another through the switch. Switch is a unicast one to one connection.

What is firewall?

A firewall is a hardware or software installed to provide security to the private networks connected to the internet. They can be implemented in both hardware and

software, or a combination of both. All data entering or leaving the Intranet passes through the firewall which allows only the data meeting the administrators rules

to pass through it.

What is Distance Vector Routing Protocols?

The main goal of Distance Vector Routing Protocols Is to find out the best path for he data packet to reach the destination. Distance here could be the hops. The

three different types of Distance Vector routing protocols include:- Routing Information Protocol (RIP v1 and v2) and Interior Gateway Routing Protocol. The

protocol is easy to manage however not well scalabl

Explain Transmission Control Protocol, TCP


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TCP ensures reliable and end to end delivery of segments of information. Segments are acknowledged to the source when received by the destination. Data is

broken up into segments and sequenced properly before transmission. This arrangement of segments allows destination to trace lost data in transmission.

TCP and UDP - Jan 28, 2009, 17:00 pm by Rajmeet Ghai

What is TCP protocol?

Transmission control Protocol is used to establish communication between nodes or networks and exchange data packets. It guarantees delivery of data packets

in the order they were sent. Hence it is most commonly used in all applications that require guaranteed delivery of data. It can handle both timeouts (if packets

were delayed) and retransmission (if packets were lost). The stream of data is transmitted in segments. The segment header is 32 bit. it is a connectionless

communication protocol at the third level (network) of the OSI model.

TCP and UDP - Jan 28, 2009, 17:00 pm by Rajmeet Ghai

TCP vs. UDP.

TCP guarantees the delivery of data. UDP on the other hand, does not guarantee delivery of data. TCP delivers messages in the order they were sent. UDP has

no ordering mechanisms. In TCP data is sent as a stream while UDP sends data as individual packets. UDP is faster than TCP. TCP is a connection oriented

protocol while UDP is connectionless.

What are the different types of VPN?

Remote Access VPN:- Also called as Virtual Private dial-up network (VPDN) is mainly used in scenarios where remote access to a network becomes

essential. Remote access VPN allows data to be accessed between a companys private network and remote users through a third party service provider;

Enterprise service provider. E.g Sales team is usually present over the globe. Using Remote access VPN, the sales updates can be made.

Site to Site VPN Intranet based: This type of VPN can be used when multiple Remote locations are present and can be made to join to a single

network. Machines present on these remote locations work as if they are working on a single network. Site to Site VPN Extranet based: This type of VPN can be used when several different companies need to work in a shared environment. E.g.

Distributors and service companies. This network is more manageable and reliable.

What is Superneting? Explain the concept of custom Subneting.

Supernetting or Classless Inter-Domain Routing (CIDR)

It is a way to aggregate multiple Internet addresses of the same class.


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The adjacent network address (eg:192.168.2.0/24 and an address 192.168.3.0/24) can be merged (into 192.168.2.0/23) using supernetting.

Supernetting is the basis for most routing protocols currently used on the Internet.

It is mostly used to combine Class C network addresses.

What is Subneting? Explain the advantages of using Subneting.

Subneting is dividing a network into several subnets.

This is usually done for the following purposes:

Reducing network traffic by decreasing the number of broadcasts

Exceeding the limitations in a local area network

Enabling people to connect to the network remotely without opening the entire network

Advantages of using Subneting:-

Easier network management and trouble shooting

Routing tables size is reduced which means faster network transfers

Solves network congestion problems:- Since the complete network is divided into smaller networks

Network addresses can be decentralized e.g. the administrator of the network can monitor the subnet.

Why do we need a subnet mask?

A subnet mask allows identification of host part and network part of an IP address. Subnet mask can be used to find if an IP address is present on a subnet or not.

What are Sockets? How do Sockets Work?

A socket is used to connect an application to a network protocol. A socket enables communication between a client and a server. The communication is started

when the client is assigned a local port number, and binds a socket to it. The client writes on the socket and gets information from server by reading it. The Socket

class is used to communicate. It provides rich set of methods for both asynchronous and synchronous data transfer. ConnectAsynch is used to start an

asynchronous connection. SendAsynch and ReceiveAsynch are used to send and receive data. Shutdown and close methods are used to shutdown and close the

sockets.


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Define Broadcast, Unicast and Multicast.

Unicast: A term used in communication to describe a piece of information to send from one point to another. There are only sender and receiver. All LANs support

unicast transfer mode and most applications that employ TCP transport protocol uses unicast messaging.

Broadcast: A term used for describing communication that is sent a piece of information from one point to all other points. There is one sender and multiple

receivers. All LANs support broadcast transmission.

Multicast: A term described in communicating a piece of information sent from one or more points to a set of other points. The senders and receivers are one or

more.

1. What is a wildcard mask, and how is it different from a netmask?

2. How do you configure a Cisco switch or router? What are the steps needed?

3. How would I place an interface into trunking mode?

4. How do you shutdown an interface on a router or switch?

5. What is VTP?

6. What is VMPS?

7. What is SPAN/RSPAN?

8. What is flow/netflow?

9. What is TACACS? Radius?

What is the difference between a hub and a switch?

Hubs and switches are different types of network equipment that connect devices. They differ in the way that they pass on thenetwork traffic that they receive.

Hubs

The term hub is sometimes used to refer to any piece of network equipment thatconnects PCs together, but it actually refers to a multi-port repeater. This type of devicesimply passes on (repeats) all the information it receives, so that all devices connected to its ports receive that information.

Hubs repeat everything they receive and can be used to extend the network. However, this can result in a lot of unnecessarytraffic being sent to all devices on the network. Hubs pass on traffic to the network regardless of the intended destination; thePCs to which the packets are sent use the address information in each packet to work out which packets are meant for them. In


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a small network repeating is not a problem but for a larger, more heavily used network, another piece of networking equipment(such as a switch) may be required to help reduce the amount of unnecessary traffic being generated.

Switches

Switches control the flow of network traffic based on the address information in each packet. A switch learns which devices areconnected to its ports (by monitoring the packets it receives), and then forwards on packets to the appropriate port only. Thisallows simultaneous communication across the switch, improving bandwidth.

This switching operation reduces the amount of unnecessary traffic that would have occurred if the same information had beensent from every port (as with a hub).

Switches and hubs are often used in the same network; the hubs extend the network by providing more ports, and the switchesdivide the network into smaller, less congested sections.

When Should I Use a Hub or Switch?

In a small network (less than 30 users), a hub (or collection of hubs) can easily cope with the network traffic generated and isthe ideal piece of equipment to use for connecting the users.

When the network gets larger (about 50 users), you may need to use a switch to divide the groups of hubs, to cut down theamount of unnecessary traffic being generated.

If there is a hub or switch with Network Utilization LEDs, you can use the LEDs to view the amount of traffic on the network. Ifthe traffic is constantly high, you may need to divide up the network using a switch.

When adding hubs to the network (to add more users), there are rules about the number of hubs you can connect together .Switches can be used to extend the number of hubs that you can use in the network.

Technically speaking, hubs operate using a broadcastmodel and switches operate using a virtual circuitmodel. When four

computers are connected to a hub, for example, and two of those computers communicate with each other, hubs simply passthrough all network traffic to each of the four computers. Switches, on the other hand, are capable of determining thedestination of each individual traffic element (such as an Ethernet frame) and selectively forwarding data to the one computer
http://www.darron.net/network/fifthpage.htmlhttp://www.darron.net/network/fifthpage.html


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that actually needs it. By generating less network traffic in delivering messages, a switch performs better than a hub on busynetworks.

Difference between Windows XP and Windows 7There are lots ofdifference between the windows XP and the Windows 7. Here are some of the differences listed below

The shutdown and the start up is very fast in Windows 7 when compared to the Windows XP

There are not much graphical components present in the windows XP but Windows 7 provides good Graphical User Interface (GUI).

In windows 7 there is no necessity for the drivers to be installed but in Windows XP it is necessary to install drivers.

The Kernel of windows 7 is very good when compared to the Windows XP.

User defined themes can be implemented in Windows 7 but in Windows XP themes cannot be created by the user.

The windows defender in Windows 7 provides maximum security to the operating system but in Windows XP this feature is not

available.

1. One of the major difference between both the operating system is User Access Control. Where Windows XP doesn't have any UAC on otherside Windows 7 enables the UAC feature which was introduced in Windows Vista.

2. Windows 7 supports DirectX 11 where Windows XP support Directx 9.

3. One major difference is regarding the graphics , where Windows XP lacks them on other hand Windows 7 is known for its visual appearance.

4. Their is a difference in speed of both the operating system where Windows 7 boots quicker than Windows XP

5. Networking features like Direct access and VPN reconnect which were not available in Windows XP but are introduced in Windows 7 also adds

a point to this list of differences between Windows XP and Windows 7.

Digital Audio Control Protocol (DACP) is a protocol used by the Apple Remote application (app) on iOSmobile devices(iPad, iPhoneand iPod

Touch) to control iTunes running on a remote computer.
http://en.wikipedia.org/wiki/ITunes_Remotehttp://en.wikipedia.org/wiki/IOS_(Apple)http://en.wikipedia.org/wiki/IOS_(Apple)http://en.wikipedia.org/wiki/Mobile_devicehttp://en.wikipedia.org/wiki/Mobile_devicehttp://en.wikipedia.org/wiki/IPadhttp://en.wikipedia.org/wiki/IPadhttp://en.wikipedia.org/wiki/IPhonehttp://en.wikipedia.org/wiki/IPhonehttp://en.wikipedia.org/wiki/IPod_Touchhttp://en.wikipedia.org/wiki/IPod_Touchhttp://en.wikipedia.org/wiki/ITuneshttp://en.wikipedia.org/wiki/ITunes_Remotehttp://en.wikipedia.org/wiki/IOS_(Apple)http://en.wikipedia.org/wiki/Mobile_devicehttp://en.wikipedia.org/wiki/IPadhttp://en.wikipedia.org/wiki/IPhonehttp://en.wikipedia.org/wiki/IPod_Touchhttp://en.wikipedia.org/wiki/IPod_Touchhttp://en.wikipedia.org/wiki/ITunes


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By connecting the remote computer to loudspeakers, directly or indirectly, for example via Apple's Airport Express, the mobile device can be used

as a two-way WLAN music remote control. With the introduction of TunesRemote+,[1]Androidusers can also access DACP servers.
http://en.wikipedia.org/wiki/Airport_Expresshttp://en.wikipedia.org/wiki/Digital_Audio_Control_Protocol#cite_note-TunesRemote-0http://en.wikipedia.org/wiki/Digital_Audio_Control_Protocol#cite_note-TunesRemote-0http://en.wikipedia.org/wiki/Android_(operating_system)http://en.wikipedia.org/wiki/Android_(operating_system)http://en.wikipedia.org/wiki/Airport_Expresshttp://en.wikipedia.org/wiki/Digital_Audio_Control_Protocol#cite_note-TunesRemote-0http://en.wikipedia.org/wiki/Android_(operating_system)

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