I have setup a VPN on my home Ubuntu 12.10 server using instructions found here using CHAP authentication:

https://raymii.org/s/tutorials/IPSEC...ntu_12.10.html

I'd like to now change this to use PAM, so I followed the relevant instructions. And this is what I get in my syslog:

Code:
May  7 09:08:41 myhost pppd[27235]: Attempting PAM authentication
...
May  7 09:08:41 myhost pppd[27235]: PAM Authentication OK for someuser
May  7 09:08:41 myhost pppd[27235]: Attempting PAM account checks
May  7 09:08:41 myhost pppd[27235]: PAM Account checks failed: 28: Module is unknown
May  7 09:08:41 myhost pppd[27235]: PAP peer authentication failed for someuser
I've looked everywhere for this and can't find any info on it. I even searched for PAM error codes, found the relevant one, but no information on how to fix it.

Thanks, Justin