CCNA INTERVIEW QUESTIONS..

1.WHAT IS THE DIFFERENCE BETWEEN SWITCH AND HUB?
ANS:    Switch: It operates at layer2 datalink layer,Address learning,forward/Filter decision using MAC address,Loop avoidance,breaks up collision domains,it creates seperate collision domains but a single broadcast domain.
             Hub: It operates at layer1 physical layer,no filtering,no addressing,it creates a single collision domain and single broadcast domain,it forwards the data to all the ports for which it is also known as "multiport repeater".

2.WHAT IS THE UTILITY OF THE "PING" COMMAND?
ANS: PING stands for PACKET INTERNET GOPHER,it is a utility that verifies the connection to one or more remote hosts.It uses the ICMP echo request and echo reply packets to determine whether a particular ip system on the network is functional.It is useful fo diagnosing ip network or router failures.

3.WHAT IS A VLAN?WHAT DOES VLAN PROVIDE?
ANS: VLAN stands for VIRTUAL LOCAL AREA NETWORK.It is a logical grouping or segmenting a network connected to administratively defined ports on a switch,they provide broadcast control,security and flexibility.

4.WHAT IS SUBNETTING?WHY IS IT USED?
ANS: Used in ip networks to break up larger networks