I had a lot of trouble debugging why Kerberos login was not working. Granted, part of the problem was not understanding the right Apache config options to get mod_auth_kerb to log debug information. But once the mod_auth_kerb debugging was solved it turned out to be too much clock skew.

I'm going to make a wild guess that time sync is not the first place an admin is going to look after installing ipsilon and discovers kerberos login silently fails.

The ipsilon server should ensure the ntpd time sync daemon running, if it isn't ntpdate should be run and then it should be stared. There should also be a packaging dependency on ntp.