[ntp:questions] Troubleshooting who's at fault

Ronaldo Mexico ronaldo.hawk.mexico at gmail.com
Wed Jun 24 23:11:55 UTC 2009


I've tried various searches using google and hear in the group to see
if someone has run into something similar, but the only people who
have questions similar to mine never got answered, so I'm hoping
bringing it up again with a bit more detail will help get it solved.

We have physical NTP servers from Brandywine (Brandywine PTS) and up
until now, we've never had a problem using them as our NTP server.
The operating systems that have successfully worked with them in the
past are:
Windows 2000 (running on pretty much PC hardware)
Windows XP (running on pretty much PC hardware)
Solaris 8 (running on native Sun hardware and a Rave Systems)

What I'm running into now is that we are switching operating systems
for our servers to Red Hat Enterprise Linux 5.  It is running on
pretty much PC hardware.

For some reason, the ntpd daemon on RHEL refuses to sync with the
Brandywine PTS unit, despite the fact that ntpdate works correctly and
other ntp polling requests work fine.

**********************************************************************************************

This is what I see (I have the PTS as preferred, the localhost as a
backup server):

[root at screamer-dc1 init.d]# service ntpd start
ntpd: Synchronizing with time server:                      [  OK  ]
Syncing hardware clock to system time                      [  OK  ]
Starting ntpd:                                             [  OK  ]
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
 LOCAL(0)        .LOCL.          10 l    1   64    1    0.000
0.000   0.001
 ntp             73.78.73.84      2 u    -   16    1    0.765
0.013   0.001
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
 LOCAL(0)        .LOCL.          10 l   23   64    1    0.000
0.000   0.001
 ntp             73.78.73.84      2 u    5   16    3    0.694
0.043   0.016
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
 LOCAL(0)        .LOCL.          10 l   37   64    1    0.000
0.000   0.001
 ntp             73.78.73.84      2 u    2   64    7    0.694
0.043   0.029
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
 LOCAL(0)        .LOCL.          10 l   38   64    3    0.000
0.000   0.001
 ntp             73.78.73.84      2 u    4   64   17    0.694
0.043   0.264
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
*LOCAL(0)        .LOCL.          10 l    -   64   17    0.000
0.000   0.001
 ntp             73.78.73.84      2 u   30   64   37    0.694
0.043   0.676
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
*LOCAL(0)        .LOCL.          10 l   18   64   37    0.000
0.000   0.001
 ntp             LOCAL(0)         2 u   48   64   77    0.694
0.043   2.276
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
*LOCAL(0)        .LOCL.          10 l   39   64   37    0.000
0.000   0.001
 ntp             LOCAL(0)         2 u    5   64  177    0.724
0.034   2.704
[root at screamer-dc1 init.d]# ntpq -p
     remote           refid      st t when poll reach   delay
offset  jitter
==============================================================================
*LOCAL(0)        .LOCL.          10 l   61   64  377    0.000
0.000   0.001
 ntp             LOCAL(0)         2 u   94  128  377    0.729
-11.907   5.335


[root at screamer-dc1 init.d]# ntpq
ntpq> ass

ind assID status  conf reach auth condition  last_event cnt
===========================================================
  1 62825  9614   yes   yes  none  sys.peer   reachable  1
  2 62826  9014   yes   yes  none    reject   reachable  1

ntpq> ntpversion
NTP version being claimed is 2

And this is my ntp.conf file:
[root at screamer-dc1 init.d]# cat /etc/ntp.conf
server  127.127.1.0 # local clock
fudge   127.127.1.0 stratum 10

server 147.159.120.131 minpoll 4 maxpoll 10 prefer iburst # ntp -
brandywine

driftfile /var/lib/ntp/drift
logfile /var/log/ntp.log

**********************************************************************************************
The RHEL operating system has no problems syncing with other stratum 2
servers (I've used public servers), just with this particular unit,
which has had no other compatibility issues.

The variables in this problem:
1.  The operating system/ntpd daemon
2.  The physical clock hardware in the machine

What do you guys think?




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