Cannot use my Linux Box as NTP Server

TommyB · 01-11-2005, 04:41 PM

Hello,
I am using Mandrake 10 and I just installed ntp 4.2.0. I was able to synchronize the time of the Linux box with the universe. As far as I understood the HowTos, if the ntpd service runs, the Linux box acts as an ntp server on its own.
The idea is to use this machine as time server for all other machines in the LAN. Unfortunately it seems that the ntp server runs not properly as time requests by other machines time out after several seconds.

When initiating ntpdate -q localhost on my NTP Server I get
Looking for host localhost and service ntp
host found : localhost
server 127.0.0.1, stratum 16, offset 0.000001, delay 0.02563
11 Jan 23:33:23 ntpdate[5969]: no server suitable for synchronization found

Trying to use my NTP Server for synchronizing the clock of a Windows PC gives a timeout. I checked the log file of the firewall, which did not block any messages from the Windows PC.

My ntp.conf file is:
server at.pool.ntp.org
server at.pool.ntp.org
server at.pool.ntp.org
server at.pool.ntp.org
driftfile /etc/ntp/drift
multicastclient # listen on default 224.0.1.1
broadcastdelay 0.008
authenticate no
restrict at.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap
restrict 127.0.0.1
restrict 192.168.1.100

Has anybody an idea where the problem lies.

Thanks
Thomas

linuxgeekery · 01-11-2005, 05:24 PM

I actually think ntpd is something to synchronize with a ntp server. Try man ntpd.

madluther · 01-11-2005, 06:42 PM

It can take up to 30 minutes before ntpd will start serving requests to clients.
Firstly check the appropriate log files and make sure you have a running server.

Then run 'ntpq -p' to make sure your server is syncing with the external servers, output should look something like this

Code:

[root@pc2 /home/madluther]# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 time-a.nist.gov .ACTS.           1 u   62   64    3   37.807  -19127.  13.569
 time-b.nist.gov .ACTS.           1 u   62   64    3   33.975  -19131.  12.807
 tick.usno.navy. 0.0.0.0         16 u    -   64    0    0.000    0.000 4000.00

The above illustrates two working servers and one that is not syncing. (A jitter of 4000 indicates there is no sync established)

Once you have a running server try the ntpdate -q localhost command

TommyB · 01-20-2005, 11:35 AM

You are right, it seems that I did not wait long enough. After some time the ntpdate -q localhost gives me the correct time.
I just have to do some tweaking on the Windows machine as it still refuses to synchronize with my Linux Box. Maybe my Windows box is too snobbish for synchronizing with a stratum 3 or 4 server.

Thanks
Thomas

TommyB · 01-20-2005, 11:35 AM

You are right, it seems that I did not wait long enough. After some time the ntpdate -q localhost gives me the correct time.
I just have to do some tweaking on the Windows machine as it still refuses to synchronize with my Linux Box. Maybe my Windows box is too snobbish for synchronizing with a stratum 3 or 4 server.

Thanks
Thomas