[NTLUG:Discuss] NTP

[Greg Edwards]

Mark Bainter wrote:
> 
> Mark Bainter [mark-ntlug at cymry.org] wrote:
> > Has anyone here ever gotten ntp up and running?
> 
> Well, from what I've seen (in private conversation) my configuration
> is ok.  But I never sync up with any remote servers that I specify.  If
> I do ntpdate <server> it works though.
> 
> I have a theory though.  This host is behind a PIX, with a static
> mapping to a public IP.  Is this perhaps part of the problem?  Are
> any of you guys running in a NAT environment?  I have the ntp port
> open on the firewall (both tcp and udp) but that doesn't seem to
> help.  Thoughts?
> 
> The only way I can see that being an issue is if the ntp software
> puts it's ip in a data packet.  But if that's the case you'd think
> it'd be addressed by now.


Maybe it is working but your just impatient?  I've notice, and (IIRC) I
read in the docs somewhere that the ntpd (NTP v4) client will not adjust
the clock all at once.  Over a period of time and several syncs it will
get the clock closer and closer so that eventually it will be the same. 
I've seen my clocks take nearly 24 hours to sync up to my server once
I've made a 5 minute adjustment to the server clock.  IIRC, ntpdate
makes a full adjustment to your clocks when run from the command line.

As I mentioned I don't use an external source to sync my internal
server.  I do however use ntp to sync all of my systems to my internal
server.  The only reason I don't use an external source is that I don't
feel the need to be hitting the net that often when my internal server
keeps reasonable time.  It loses maybe 20 seconds in a month.

-- 
Greg Edwards
New Age Software, Inc.
http://www.nas-inet.com