Xntpd on Solaris 10 gets synchronised with a higher stratum NTP server

Question

The Solaris 10 machine has the following configuration in etc/inet/ntp.conf
server 10.24.179.33 prefer
server 127.127.1.0
fudge 127.127.1.0 stratum 8
The Linux Fedora Core 4 test machine(10.24.179.33 ) configured as NTP server running ntpd V4 has the following configuration
server 127.127.1.0
fudge 127.127.1.0 stratum 10
The solaris 10 xntpd get synchronised to Linux NTP server even though it is at a higher stratum level.
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 18 64 77 2.04 0.084 376.68
LOCAL(0) LOCAL(0) 8 l 17 64 77 0.00 0.000 385.01
The expectation was the solaris machine should not consider the server at a higher stratum level(11) for synchronistation. It should have got synchronised to the Local clock which is at stratum level 8.

Answer 1

I now tried waiting for an hour, but the xntpd id still synchronised to the higher stratum clock from the NTP server 10.24.179.33. Please verify the logs below.
Does the prefer keyword in line "server 10.24.179.33 prefer" has anything to do with this behaviour ?
What does the RFC1305 say on process of selecting a synchronisation source ?
My understanding was that xntpd should not be synchornising with a higher stratum clock from the NTP server (which is at stratum 11) when it already has as another server(here the local clock) which is at a lower stratum (we have simulated this by fudging the local clock to stratum 8).
Please correct me on this.
You have mentioned that "Stratum number is not absolute for choosing a clock. A higher stratum may be preferred in some situations."
Could you explain me more on these situations and I also want to know the rules used by xntpd to choose a clock?
Or you could provide any links where I can read more on this aspect.
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
10.24.179.33 LOCAL(0) 11 u 13 64 1 0.52 -0.001 15875.0
LOCAL(0) LOCAL(0) 8 l 12 64 1 0.00 0.000 15885.0
(WCCONGO02):(root) UTC 1:21:37 VER R-02.01.16.03
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 1 64 77 0.52 -0.244 376.77
LOCAL(0) LOCAL(0) 8 l 64 64 37 0.00 0.000 885.01
(WCCONGO02):(root) UTC 1:26:45 VER R-02.01.16.03
# uname -a
SunOS WCCONGO02 5.10 Generic_127127-11 sun4v sparc SUNW,Netra-T5440
(WCCONGO02):(root) UTC 1:29:44 VER R-02.01.16.03
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 40 64 377 0.61 0.415 0.56
LOCAL(0) LOCAL(0) 8 l 39 64 377 0.00 0.000 10.01
(WCCONGO02):(root) UTC 2:7:56 VER R-02.01.16.03
# ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
*10.24.179.33 LOCAL(0) 11 u 13 64 377 2.26 1.289 0.66
LOCAL(0) LOCAL(0) 8 l 12 64 377 0.00 0.000 10.01
(WCCONGO02):(root) UTC 2:22:25 VER R-02.01.16.03
Edited by: SujithKS on May 27, 2009 10:34 AM
Edited by: SujithKS on May 27, 2009 11:26 AM