I have 40 or 50 tunnels with over 200 SAs active on a 7204VXR with NPE-G1 using the software crypto engine (no VAS card installed).
The working config was transferred over from a 2821 with AIM-VPN hardware crypto.
Everything was fine for a while then one day all tunnels were down and debug messages were showing Unable to generate DH phase I values! almost identical to this unresolved issue.
IOS was (C7200-ADVENTERPRISEK9-M), Version 15.2(4)M4.
After trying all manner of things to get it back it was ultimately a reload that resolved things.
A couple of days later the same issue occurred again, reload and then a couple of hours later again.
I then upgraded to the latest (C7200-ADVENTERPRISEK9-M), Version 15.2(4)M8 and it's been ok for 4 days and the issue has occurred again with a slightly different error string Unable to generate DH phase 2 parameters! I'm guessing they changed the string rather than it being a different error.
Has anyone experienced this before or have any pointers of something that may have been missed?