Re: Local clock question with dialup connection

On Thursday 19 April 2007 19:11, Danny Mayer wrote:
Nigel Henry wrote:
On Thursday 19 April 2007 05:12, Danny Mayer wrote:
Harlan Stenn wrote:
In article <200704162309.24517.cave.dnb@xxxxxxxxxx>,
cave.dnb@xxxxxxxxxx (Nigel Henry) writes:

Nigel> djmons@localhost djmons]$ /usr/sbin/ntpq
ntpq> pe
Nigel> localhost.localdomain: timed out, nothing received ***Request
timed Nigel> out

This looks like ntpd is not running at the time you did this.

No, you would not get Request timed out, you would get connection
refused. It may be that the server is just dropping your queries.

Danny

FC5 isn't giving me this problem using 4.2.4p0-1.fc6. I do have the 2
local clock lines (server, and fudge) uncommented, and when I boot the
machine with no Internet connection, then after connecting to the
Internet (dialup) , I run ntpq> pe, it shows local as a system peer, and
3 servers from fedora.pool.ntp.org dynamic. It does take ages before one
of the servers is set as system peer, but it's working.

On FC2 using 4.2.0-7, I am using 3 specific stratum2 servers, rather than
a pool. Could it be that because I only have 3 specific servers, that
they are being tried once while there is no initial Internet connection
on bootup, are failing to be found, and ntpd is not trying them again. I
presume a server pool has many available servers, so if I have a server
pool in /etc/ntp.conf, does ntpd just keep on trying to get a response in
this case, like it tries the pool, doesn't get a response, tries again,
no response, tries again, and so on, by which time I have made the
Internet connection, and it's still trying to find a pool server, and now
with an active Internet connection it gets a response, and sets up 3
available Internet servers?

As I'm having problems installing 4.2.4p0 from the tarball on FC2, I
think I'll try reinstalling 4.2.0-7, put a server pool in /etc/ntp.conf,
and see just for hell of it, if it works.

All in a days work.

Nigel.

That's not the issue. The question really is what you have in your
ntp.conf file. If you have restrict statements in the file ntpd may just
drop queries like you are making and therefore ntpq will just time out.
It's hard to know without seeing the config file.

If it takes a long time to get a preferred server, you are probably not
using the iburst option on the server lines. It speeds up
synchronization considerably.

Danny

I havn't used iburst before, but bear in mind that when I boot up there is no
Internet connection. As I mentioned above, I've reinstalled 4.2.0-7, and used
the servers from FC6's /etc/ntp.conf file for 4.2.4p0. /etc/ntp.conf is very
basic, and I removed "dynamic" from the end of the server lines, as otherwise
there were problems using the file with 4.2.0-7 on FC2. See below.

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
server 0.fedora.pool.ntp.org
server 1.fedora.pool.ntp.org
server 2.fedora.pool.ntp.org

# Undisciplined Local Clock. This is a fake driver intended for backup
# and when no outside source of synchronized time is available.
#server 127.127.1.0 # local clock
#fudge 127.127.1.0 stratum 10

# Drift file. Put this in a directory which the daemon can write to.
# No symbolic links allowed, either, since the daemon updates the file
# by creating a temporary in the same directory and then rename()'ing
# it to the file.
driftfile /var/lib/ntp/drift

It's getting better, and booting up with no Internet connection, then
connecting to the Internet, then running ntpq< pe gives me just one available
server, and that is one using an IP address rather than a hostname, so there
appears to perhaps be a slight DNS problem.

ntpq> pe
remote refid st t when poll reach delay offset jitter
==============================================================================
192.33.214.57 .INIT. 16 u - 64 0 0.000 0.000 4000.00
ntpq> pe
remote refid st t when poll reach delay offset jitter
==============================================================================
192.33.214.57 192.33.214.12 2 u 31 64 1 148.565 -1745.9 0.001
ntpq> pe
remote refid st t when poll reach delay offset jitter
==============================================================================
192.33.214.57 192.33.214.12 2 u 40 64 3 148.565 -1745.9 21.924
ntpq> pe
remote refid st t when poll reach delay offset jitter
==============================================================================
192.33.214.57 192.33.214.12 2 u 49 128 7 148.565 -1745.9 15.573
ntpq> pe
remote refid st t when poll reach delay offset jitter
==============================================================================
*192.33.214.57 192.33.214.12 2 u 319 512 37 148.565 -1745.9 15.685
ntpq>

Stopping and then starting ntpd, and running ntpq> pe now gives me the
expected 3 Internet servers from the pool.

ntpq> pe
remote refid st t when poll reach delay offset jitter
==============================================================================
dedibox.ebzao.i 195.220.94.163 2 u 26 64 1 140.115 -14.301 0.001
chime6.surfnet. .PPS. 1 u 25 64 1 139.069 -16.197 0.001
i216-58-31-84.c 199.212.17.22 3 u 23 64 1 258.237 0.795 0.001
ntpq>

It looks like I need to delay ntpd being started at bootup, or at least delay
the polling of the servers. I see there is a script for this in the 4.2.4p0
version, but can't see such a workaround on a rpm installed version as the
4.2.0-7 version is on FC2.

I think ideally what I need is a script that will detect when the Internet
connection is up, and then start ntpd. I can't see there being any problems
then. If you can suggest a suitable script that would be great, otherwise
I'll ask on some other lists. I've little experience on writing scripts.

Someway or other this is going to be fixed.

Nigel.



_______________________________________________
questions mailing list
questions@xxxxxxxxxxxxxxxxx
https://lists.ntp.isc.org/mailman/listinfo/questions

.

Relevant Pages

  • Re: [opensuse] chrony and hwclock
    ... server is configured but not used ("ntpq -p" will show the peers). ... I finally got a chance to run this (after boot, logged in and network ... At this point, could you also do 'pidof ntpd', please. ...
    (SuSE)
  • Re: [opensuse] chrony and hwclock
    ... server is configured but not used ("ntpq -p" will show the peers). ... I finally got a chance to run this (after boot, logged in and network ... At this point, could you also do 'pidof ntpd', please. ...
    (SuSE)
  • Linux/Windows: Different synchronization behaviour
    ... We are running ntpd ... clients on both Linux and Windows Server 2003 with identical ... Below I attach ntpq output and the ntp.conf configuration file. ... restrict default ignore ...
    (comp.protocols.time.ntp)
  • Re: Local clock question with dialup connection
    ... This looks like ntpd is not running at the time you did this. ... It may be that the server is just dropping your queries. ... Internet, I run ntpq> pe, it shows local as a system peer, and ... they are being tried once while there is no initial Internet connection ...
    (comp.protocols.time.ntp)
  • Re: Local clock question with dialup connection
    ... This looks like ntpd is not running at the time you did this. ... It may be that the server is just dropping your queries. ... no Internet connection, then after connecting to the Internet, I ... pool has many available servers, so if I have a server pool in /etc/ntp.conf, ...
    (comp.protocols.time.ntp)