[CentOS] Strange NTP problem

[Alfred von Campe]

On May 20, 2008, at 20:25, Filipe Brandenburger wrote:

> What is the output of "ntpq -np" ? You should have a line with a star
> (*), otherwise it is not synchronizing. Start running NTP again, wait
> for half an hour and issue that command to see what your output is. It
> could be a problem related to filtering UDP traffic, either with
> iptables on the machine itself, or some other router in the network
> your machine is in.

Bad system:

# ntpq -np
      remote           refid      st t when poll reach   delay    
offset  jitter
======================================================================== 
======
  10.101.32.104   67.128.71.65     3 u  689 1024  377    0.659   
54095.7 4263.68
*127.127.1.0     .LOCL.          10 l   28   64  377    0.000     
0.000   0.001

Good system:

# ntpq -np
      remote           refid      st t when poll reach   delay    
offset  jitter
======================================================================== 
======
*10.101.32.104   67.128.71.65     3 u  232  256  377    0.280    
15.503   1.204
  127.127.1.0     .LOCL.          10 l   64   64  377    0.000     
0.000   0.001

The bad system is synch'ing with itself (which was apparent from the  
messages in /var/log/messages).  The question is why?

Alfred