a) Why does the Authentication Header not protect all header fields of the outer IP header?

b) Consider IP fragmentation: argue why the processing of incoming packets requires all fragments of an IP packet to be reassembled before the processing of IPSec can proceed.

c) What measures are taken in the AH or ESP protocol to prevent a replay attack?

d) Why it is...

TCP is a robust protocol: Sequencing and error correction are ensured, but there is a penalty in overhead (for example, if
no re-sequencing or error correction is needed). UDP does not provide these services but is correspondingly simpler. Cite
specific situations in which the lightweight UDP protocol could be acceptable, that is, when error correction or sequencing
is not needed

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