I was reading RFC 4251 (really all of the SSH RFCs) and in section 9 it goes into great length about security considerations listing 3 cases of MITM attacks. In several places in the RFCs the authors mention not having the proper infrastructure to distribute server keys from a central authority.
RFC 6187, if I understand it correctly, changes this does it not? Or am I confusing how the pieces interact with each other?
Granted the probability of a MITM attack seems remote in succeeding anyway based off my reading... or does the use of X.509 close some doors but open others?