Related files:
/etc/security/access.conf
/etc/pam.d/sshd
Below is my /etc/pam.d/sshd
#%PAM-1.0
auth required pam_listfile.so item=user sense=allow file=/etc/allowed_to_ssh_listfile onerr=fail
auth required pam_stack.so service=system-auth
auth required pam_nologin.so
account required pam_stack.so service=system-auth
#Comment
#account required pam_access.so - > this is to be added so that the account required pam_access.so
password required pam_stack.so service=system-auth
session required pam_stack.so service=system-auth
session required pam_loginuid.so
#/etc/allowed_to_ssh_listfile - example content
root
user1
user2
Note: root has been included here but will be restricted on the /etc/security/access.conf
#/etc/security/access.conf
#The format of the ip on centos4 has .(dot) at the end
#for centos5, it can be no .(dot)
#the cron entry is to allow root to run cron, else cron will fail for root
+ : root : 10.10.9.3.
+ : root : 10.10.9.6.
+ : root : 127.0.0.1.
+ : root : 10.120.1.6.
+ : root : 127.0.0.1
+ : root : cron crond :0 tty1 tty2 tty3 tty4 tty5 tty6
+ : root : LOCAL
#
- : root : ALL
