clock too slow - big time offset with ntpdate

[Jeremy Chadwick]

On Wed, May 02, 2007 at 02:30:38PM -0700, Kevin Oberman wrote:
> A few more comments:
> 
> If ntpd is started with the '-g' flag, it will initially step the time
> so you get your clock set as you would have with ntpdate. This is set in
> /etc/rc.conf as 'ntpd_flags="-p /var/run/ntpd.pid -f /var/db/ntpd.drift -g". 
> 
> You also should add 'iburst' to each server line in ntp.conf. This will
> cause several queries to be made to each server at startup so that
> there will not be a long delay before the clock is synchronized. Without
> the 'iburst', your time won't be set for about 4or 5 minutes.

I'll include the ntp.conf configuration we use, as well relevant rc.conf
portions, on a few of our production machines.

There are some "FreeBSD-isms" in ntp.conf which are worth noting.  I
keep the comments around solely so I don't forget.  :-)


ntp.conf:

# clock.isc.org
# clepsydra.dec.com
#
# maxpoll 9 is used to work around PLL/FLL flipping, which
# happens at exactly 1024 seconds (the default maxpoll value).
# Another FreeBSD member recommended using 9 instead.
# http://lists.freebsd.org/pipermail/freebsd-stable/2006-December/031512.html
#
server 204.152.184.72 iburst maxpoll 9
server 204.123.2.5 maxpoll 9

# Default: ignore all ntp queries from ALL other hosts
restrict default ignore

# Allow queries to/from the NTP hosts listed in "server" lines
restrict 216.218.192.202 mask 255.255.255.255
restrict 216.218.254.202 mask 255.255.255.255
restrict 204.152.184.72 mask 255.255.255.255
restrict 204.123.2.5 mask 255.255.255.255

# Allow queries to/from localhost, used for ntpdc and other utils
restrict 127.0.0.0 mask 255.0.0.0

# Allow queries to/from the local private network
restrict 192.168.1.0 mask 255.255.255.0 nomodify


rc.conf:

ntpd_enable="yes"
ntpd_sync_on_start="yes"


Applicable process:

root      652  0.0  0.1  3148  1564  ??  Ss   22Apr07   0:16.13 /usr/sbin/ntpd -g -p /var/run/ntpd.pid -f /var/db/ntpd.drift

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |