confusion -- computer networks

Question

Do we actually need ip and Mac addresses both at same time for the computer for communication?

Why we not use Mac instead of ip address since Mac is also the unique address globally?

Why we not use ip instead of Mac
Since both are unique but why we use both for computer networkws?

Answer 1

IP and MAC assigned to a machine are always unique globally (except when using private IPs). IP addresses are used because their representation format helps in routing much more easily than a MAC address.

Answer 2

We need both MAC and Ip addresses because of Routing.

Suppose there are 2 systems in 2 different local networks, System A with Ip address iA and Mac address mA, and System B with Ip address iB and Mac address mB.

 

Case 1:-

(Since private Ip addresses are unique locally) It is possible that both A and B have the same Ip address.

In this case, while routing router will first check Data-link layer where it will see the same IP address and then it will be passed to physical layer and here both the mac address will be unique, so there will be no ambiguity.

 

Case 2:-

Let, a host from the same device is running more than one process at the same time. In this case, the Mac address is the same mA=mB. But each process in the same network will have a different Ip address, so iA and iB will never be same, so in this case, Ip will reduce the ambiguity.

 

 

hope it helps