Red Hat Bugzilla – Bug 133668
ntpd configuration and pool.ntp.org
Last modified: 2007-11-30 17:10:50 EST
Description of problem:
Current version of ntp lists among available servers also
pool.ntp.org. If I understand correctly how poll.ntp.org
works one is supposed to put in a configuration file
multiple servers with the same name and they will resolve
to different IP addresses not always the same. See
But if one is trying to use 'system-config-date' for that
purpose then my experiments indicate that only one entry
for poll.ntp.org can be used and moreover it gets resolved
to a fixed IP address recorded in /etc/ntp.conf and in
/etc/ntp/step-tickers in a configuration time. This seems
to contravene the whole idea of pool.ntp.org.
Yes, I can see that punching on ntpd startup firewall holes
for ntp servers may be here troublesome.
Version-Release number of selected component (if applicable):
I've removed pool.ntp.org from the ntpservers file for now (1.7.9-1)
as s-c-date really doesn't handle multi-homed machines well.
Don't you think that handling multi-homed servers should really
be a longer range goal and that closing this report will make
the issue "lost" in the future?
One possibilty of handling firewall issues would be to open a port
123, check which connections are really in use (proably with ntpq),
and tighten up rules to what is really required by the current
ntp configuration. There could be a MULTIHOMED flag which informs
startup if such treatment is needed. s-c-date does need to be
"smarter" for that (and AFAICS clock.redhat.com is multi-homed
as well :-).
I fixed the immediate problem with a short-term workaround. I've
already opened bug #133925 for enhancing s-c-date accordingly some
time in the future.