I just realised that pam_access no longer works under CentOS6 - or it works
differently from CentOS5.
Under CentOS5, I used this configuration to restrict access to root only:
# cat /etc/security/access.conf
+ : root : ALL
- : ALL : ALL
# cat /etc/pam.d/system-auth-ac
...
account required pam_access.so
account required pam_unix.so
account sufficient pam_localuser.so
account sufficient pam_succeed_if.so uid < 500 quiet
account required pam_permit.so
...
#
Under CentOS6, this has no effect and I can still login as non-root user.
What am I missing?