Question

Assume that there is no option field in the header of an IPv4 datagram. Which field(s) of the IPv4 header change from router to router?

Answer 1

The fields of the IPv4 header change from router to router is:

• No Fragmentation - TTL, checksum(due to TTL).

• Fragmentation - Total length field, fragment M bit.

Step-by-step explanation:

TTL - TTL stands for Time-TO-Live, it is important in an IP(Internet Protocol) packets that says a network router if or not the packets have been in the network so lengthy and should be rejected.

Fragmentation - It is done through the network layer when the mostly size of data-gram is higher than max size of data that can held a frame.

It is done through the network layer at the end side and is generally done at routers.