Hi Mark and thanks for your soon answer.. I found this excellent guide on internet http://www.puschitz.com/SecuringLinux.shtml... here I could fine all I was looking for about securing my database server running on CentOS.. Regards Israel, >I'm running RHEL 4.6 and am using the features you are looking to >implement. PAM is the direction to look. I have included my >/etc/pam.d/system-auth file as example: >#%PAM-1.0 ># This file is auto-generated. ># User changes will be destroyed the next time authconfig is run. >auth required /lib/security/$ISA/pam_env.so ># The following was added on 12-Apr-06 to count failed password >and "su" attempts >auth required /lib/security/$ISA/pam_tally.so onerr=fail no_magic_root ># End of changes >auth sufficient /lib/security/$ISA/pam_unix.so likeauth nullok>> auth required /lib/security/$ISA/pam_deny.so >account required /lib/security/$ISA/pam_unix.so ># The following was added on 12-Apr-06 to count failed password >and "su" attempts >account required /lib/security/$ISA/pam_tally.so per_user >deny=3 no_magic_root reset # End of changes >account sufficient /lib/security/$ISA/pam_succeed_if.so uid < 100 quiet >account required /lib/security/$ISA/pam_permit.so #password requisite /lib/security/$ISA/pam_cracklib.so retry=3 #password requisite /lib/security/$ISA/pam_cracklib.so retry=3 minlen=10 ucredit=-2 lcredit=-2 dcredit=-2 ocredit=-2 difok=3 # Changed to 15 character length password password requisite /lib/security/$ISA/pam_cracklib.so retry=3 minlen=15 ucredit=-2 lcredit=-2 dcredit=-2 ocredit=-2 difok=3 # Remember the last 15 passwords password sufficient /lib/security/$ISA/pam_unix.so nullok use_authtok md5 shadow remember=15 password required /lib/security/$ISA/pam_deny.so session required /lib/security/$ISA/pam_limits.so session required /lib/security/$ISA/pam_unix.so ~ I haven't dealt with this for a while so there my be other changes required. This should be a start for a search with your favorite search engine. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20080204/84d8737f/attachment-0004.html>