Computer Networks

It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.

In transport layer two protocols are working TCP , transmission control protocol and UDP , user datagram protocol , TCP is also know as reliable protocol , means it is using handshake process , where client requtest to server then establish the connection and then transfer the packet then terminates it. In UDP , no relaibilty but packets are safe. when long RTO is there that time packtes use to UDP.

Autonomous system has been assigned a number which differentiates it from other autonomous systems to communicate. there is BGP working at to communicate with other AS

Recovery Console for example if you install a software in exsisting windows and due to the software if the system have some problem you can choose Recovery console at Start -programs-accessories-system tools-Recovery consoleenter it and you can see the Timetable of Recovery console select the previous date of which you installed and select Restore. it can have a back up of Registery Files

NetBIOs name is system Name it is only 15 character long and resolve by NetBios protocal.TCP/IP Name is full system name. it is 65 characters long and resolved by windows scoket protocal.

Difference between the communication and transmission. Transmission is a physical movement of information and concern issues like bit polarity, synchronisation, clock etc. Communication means the meaning full exchange of information between two communication media.

There are basically 2 types of transmission technologies1.Broadband :In this type .Every host sends the packet/message to all the host.the message has a source address and a destination address. destination address helps the host to identify whether the message is indeed for them or somebody elsethe source address allows them to identify from whom the message has come.2.Point to Point :In this type of technology there are multiple connections (transmission lines) between 2 hosts. so the the packet can take different routes if a particular route is congested.

A layer 2 switch provides connectivity but doesn't act upon the packets at all. These switches are often found in small offices, your home or on the very edge of a LAN to provide Internet or client/server communication. A layer 3 switch provides connectivity but can also provide routing, access lists, QOS and even security. These are usually much more expensive switches with IOS's installed. They are best used in video conferencing to keep video packets together through QOS. For video, your cable should run directly to the layer 3 switch and not pass through any other lessor switch to avoid tiling, delays and other issues that affect video quality.

In windows 2000 and 2003 environment ads is a power full sercice ,active directory mainly used for maintaing and promotion of entire company into centralized network administration .it means domine evironmnet

The address which can't be routed through public (internet) are private ip addressesand it is scheam of saving public addressex:in class A range is10.0.0.0 to 10.255.255.255

Broadcast Domain: A set of all devices that recieve broadcast frames originating from any device within the set. Broadcast domains are typically bounded by routers (or, in a switched network, by VLANs) because routers do not forward broadcast frames.Collision Domain: In Ethernet, the network area within which frames that have collided are propagated. Repeaters and Hubs prpagate collisions, LAN switches and bridges do not.

In networking, the Point-to-Point Protocol is commonly used to establish a direct connection between two nodes. Its primary use has been to connect computers using a phone line, though it is also occasionally used over broadband connections.

Layer 2 switch forward or filter frames, layer 3 switch (router) use logical addressing and provide packet switching. Router also provide packet filtering by using acess list and when connect two or more network together and use logical addressing (IP). Besides, router use routing table to make path selection and forward packet to remote network.

NTLDR is missingPress CTRL+ALT+DEL to restart. This problem may occur if the basic input/output system (BIOS) on your computer is outdated, or if one or more of the following Windows boot files are missing or damaged: NtldrNtdetect.comBoot.ini To resolve this issue, verify that the BIOS on your computer is current, as appropriate to your situation,u can solve it by repair this folder in the first repair in Win XP if u know name of his folder ..if u dont know u can repair all files ...

By using a point-to-point protocol, that allows the branch office router act as a PPP initiator to the peer PPP router at the main office. Now, for security purpose, the PPP protocol packets can be tunneled using a tunnelling protocl like IPSec (tunnel mode) or L2TP etc.

You configure what is known as Network Address Translation (NAT) on the router. This then translates the IP address of the server, which is likely to be a 10.x.x.x or 192.168.x.x address, to be the IP address it gets from your service provider. It keeps track of which server, and where it is going, so it can use the same 'real' IP address on the Internet for both of them.

Gateway is nothing but the final point that the data crosses finally in a network, it is mostly used for user authentication which router cannot provide. Gateways can provide authentication to anonymous users, it is used when u have only one single network. It is less costly. Whereas router is used for routing between different networks, providing routing tables and deciding best path for the data to travel. It is used when you have more than one networks. It is more costly.

A Virtual Private Network ( VPN) delivers private network services over a public infrastructure. An IP VPN is a partitioned private network constructed over a shared IP-based backbone that utilizes technologies to ensure privacy of data. BenefitsIntranet ,Cost Effectiveness ,Security ,Flexibility,Reliability

POP3 and IMAP4 are used to retrieve mails.IMAP4 stores a copy of message on the server whereas POP3 does not.