Why both IP and MAC?

1. What happens if we just use MAC address alone?

Mac Address,

1. Mac/Physical address is a globally unique ID for your device.
2. Mac Address is useful and efficient for local communications.
3. Broadcast domain: the internet is not possible.
4. Mac address is burnt with hardware NIC card – loss of hardware, loss of all existing connections.

1. What happens if we just use IP address alone?

IP Address,

1. They can group and organize different networks.
2. They are much like your mailing address.
3. They are flexible and changeable – making a device mobile.
4. But they only indicate “where you are”, not “who you are”.

Mac address tells who you are which is never changed, however, IP address tells where you are which can change.

They work together to make sure the message is delivered to the right device on the right network.