Hello everyone! Below you will find my generic howto on how to add NTP service to your Cisco IDS. Obviously Cisco doesn't "support" this configuration but it is very simple so it shouldn't cause any problems. The NTP update service is already installed on the OS so this process is very simple.
1.) SSH/Telnet into your IDS and login as root.
2.) Unless you are familiar with the ed editor, excute these commands so that you don't frustrate yourself. "EDITOR=/usr/bin/vi" then "export EDITOR". Now vi will be your default editor.
3.) Type "crontab -l". This will list your current crontab, I suggest you make a backup of this unless you are good with vi. :)
4.) Tyco "crontab -e". This will allow you to edit your crontab entries within the vi editor. The statement I added is "30 11 * * * /usr/sbin/ntpdate 184.108.40.206 > /dev/null 2>&1"
This will run the ntpdate program every day at 11:30am, pulling the time from the 220.127.116.11 NTP server.
-Bryan <[email protected]>