ntpdate

[Kevin Oberman]

> Date: Thu, 30 Mar 2006 17:59:28 +0200
> From: gareth <bsd at lordcow.org>
> Sender: owner-freebsd-stable at freebsd.org
> 
> On Thu 2006-03-30 (10:35), Michael Proto wrote:
> > cd /usr/src/usr.sbin/ntp
> > make depend
> > make
> > make install
> 
> yay, ok that works ta (going into /usr/src/usr.sbin/ntp
> as opposed to /usr/src/usr.sbin/ntp/ntpdate) and the
> binary gets rebuilt. but, same problem :/
> 
> # ntpdate nom.uct.ac.za
> Looking for host nom.uct.ac.za and service ntp
> host found : 2001:4200:300:100:20e:cff:fe5c:f5c4
> 30 Mar 17:58:16 ntpdate[35787]: cannot find family compatible socket to send ntp packet

You are trying to send an ntp packet to
2001:4200:300:100:20e:cff:fe5c:f5c4, but it looks loke that system is
not opening an IPv6 port for ntp, so this fails. It looks like this
system has an IPv6 address in DNS, but is not actually running IPv6. I
can't ping it and a trace makes it to S.A., but dies before reaching the
host.

ntpd is VERY stupid in handling this. It does a DNS query on all servers
in the ntp.conf file ONCE at startup and saves the first response it
gets. Even though there are other, usable addresses, it sticks with the
first one resolved. 

You can fix this by specifying the IPv4 address (137.158.128.11) in
ntp.conf. I have been told that queries may be limited to IPv4 in
ntp.conf, but the man page does not indicate this and I have not had
time to dig into the sources.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634