I have the following situation:
A OpenSUSE 11.4 machine, configured via DHCP on a local network and running an NTP client.
My problem is:
a) As far as I know, NTPd is not only an “NTP client”, but also provides “NTP services” to the local network. As soon as NTP is configured via DHCP, YaST tells me that I cannot use the “Restrict NTP Service to configured servers only” option (under Network Services -> NTP Configuration -> Security Settings). Why? I would like to completely disable the “NTP server” part and not have my machine listening on port 123 on all interfaces.
b) As NTPd is currently listening on port 123 on all interfaces, I used the “Nessus Security Scanner” to scan my machine. Of course it finds the open port 123 and tells me that:
It was possible to gather the following information from the remote NTP host :
version=‘ntpd firstname.lastname@example.org Tue Jun 7 03:07:00 UTC 2011 (1)’, processor=‘x86_64’, system=‘Linux/22.214.171.124-0.11-desktop’, …
SERIOUSLY? NTPd is returning my exact kernel version to anyone asking for it on my local subnet?!?
So my question is:
a) Why can I not stop NTPd from listening on port 123 while using DHCP? (Of course I could the SUSEfirewall to block port 123, sure…, but why is this designed the way it is?)
b) How can I stop NTPd from publishing my kernel version?
Thanks for any help on this!