These interview questions with answers will test your basic knowledge of PC and networking.

What is the difference between TCP and UDP

TCP is a connection oriented protocol, which means that everytime a packet is sent say from host A to B, we will get an acknowledgement. Whereas UDP on the other hand, is a connection less protocol.

Where will it be used : TCP -> Say you have a file transfer and you need to ensure that the file reaches intact, and time is not a factor, in such a case we can use TCP.

UDP-> Media Streaming, question is say you are watching a movie…would you prefer that your movie comes..perfectly….but u need to wait a long time before you see the next frame ?..or would you prefer the movie to keep streaming…Yes…The second option is definely better….This is when we need UDP

What is a MAC address?

MAC is a machines Physical address, The internet is addressed based on a logical addressing approach. Say,when the packet reaches say the bridge connection a LAN, the question is..how does it identify, which computer it needs to send the packet to. For this it uses the concept of ARP, Address Resolution Protocol, which it uses over time to build up a table mapping from the Logical addresses to the Physical addresses. Each computer is identified using its MAC/Physical address ( u can use the ipconfig -all option to get ur MAC address).

What is MTU

The MTU is the “Maximum Transmission Unit” used by the TCP protocol. TCP stands for Transmission Control Prototcol. The MTU determines the size of packets used by TCP for each transmission of data. Too large of an MTU size may mean retransmissions if the packet encounters a router along its route that can’t handle that large a packet. Too small of an MTU size means relatively more overhead and more acknowledgements that have to be sent and handled. The MTU is rated in “octets” or groups of 8 bits. The so-called “official” internet standard MTU is 576, but the standard rating for ethernet is an MTU of 1500.

Ques 2: Diffrence Betw. Switch , Hub, Router..

Hub:

1.it is a layer1 device. Used to connect various machine on Lan.
2.It forwards broadcast by default.
3.It supports one collision domain and one broadcast domain.
4.it works on Bus topology resulting less speed.
Switch: 

1. a layer 2 device.
2. Forward broadcast first time only.
3. one broadcast domain & collision domains depends on no. of ports.
4.It is based on Star Topology giving 100mbps to every pc on LAN.
Router:

 1. Does not Broadcast by default.
2. breaks up Broadcast domain.
3. Also called Layer3 switch.

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