I understand that it's not possible to have Autentication Header with a regular NAT, because it messes with the IP header protected by AH. How about proxies? Do they change anything in the packet? ...
I am having trouble and need some direction using computer certificates with Windows 7 firewall IP Security rules, using certificates only for user authentication. I can get everything to work ...
Some highly secure networks and DMZs prevent all communication to outside hosts. This can cause issues with validating externally signed data I can guess that issues with signature validation occur ...