Question

P5. (5pts) Recall that we saw the Internet checksum being used in both transport-layer segment (in UDP and TCP headers) and in network-layer datagrams (IP header). Now consider a transport layer segment encapsulated in an IP datagram. Are the checksums in the segment header and datagram header computed over any common bytes in the IP datagram

Answer 1

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Step-by-step explanation:

No common bytes are used to compute the checksum in the IP datagram. Only the IP header is used to compute the checksum at the network Layer.

At TCP/UDP segment, the IP datagram may have different protocol stacks used.

Therefore, when a TCP datagram is entered in the IP datagram, it is not necessary to use common byte to compute checksum.