This is not helped by the RFCs that specify the behaviour of these core protocols. It is rare to find a network protocol rfc that is clear, specific and not sel

This is not helped by the RFCs that specify the behaviour of these core protocols. It is rare to find a network protocol rfc that is clear, specific and not self contradictory (IPSec rfcs come to mind as a positive example). Say, compare RFC3174 (sha1) and e.g. rfc4664 (l2vpn) the first is almost a copy-paste implementation, with tests and all. the second reads like a "write a presentation, ten pages minimum" or look at the base bgp4 rfc - that overspecified imaginary state machine is a good illustration of how bad things are there.