I'm running NW 6.5 SP5 servers here. Server_A is my main time server.
It's set to Single and gets its time from two external server
(External01 and External02 for example). Server_B is set as a secondary
server and to get time from Server_A and External01. All my other
servers are set to get time from Server_A and Server_B.

Server_B has been drifting and going out of sync couple of times a week.
So we updated it to SP 5 and now it's only going out of sync about once
a month. I turned on logging of timesync and here's what I found:

Start Poll
^^^Polled server Server_A:123 NTP Source
offset.h = 00000000 offset.l = 04a7a9af
Uniform Adjustment Requested: +18 Milliseconds
This server is configured as a SECONDARY
Sat Feb 10 03:36:37 2007

Start Poll
^^^Polled server Server_A:123 NTP Source
offset.h = 00000000 offset.l = 0468968d
Uniform Adjustment Requested: +17 Milliseconds
This server is configured as a SECONDARY
Sat Feb 10 03:46:37 2007

Start Poll
^^^Polled server Server_A:123 NTP Source
offset.h = 00000000 offset.l = 11e6baaf
Uniform Adjustment Requested: +69 Milliseconds
This server is configured as a SECONDARY
Sat Feb 10 03:56:37 2007

Start Poll
^Server_A Invalid NTP Stratum. Discarding the packet.
^Server_A Invalid NTP Stratum. Discarding the packet.
^Server_A Invalid NTP Stratum. Discarding the packet.
*** Unable to communicate with server Server_A:123! ***
^External01 Invalid NTP Stratum. Discarding the packet.
^^Polled server External01:123 NTP Source
offset.h = ffffffff offset.l = fc2399d3
Uniform Adjustment Requested: -15 Milliseconds
This server is configured as a SECONDARY
Sat Feb 10 04:06:37 2007

Start Poll
^^^Polled server Server_A:123 NTP Source
offset.h = fffffed3 offset.l = f677fb62
Time synchronization has been lost after 127 successful polling loops.
Uniform Adjustment Requested: -30037 Milliseconds
This server is configured as a SECONDARY
Sat Feb 10 04:16:37 2007

Start Poll
^^^Polled server Server_A:123 NTP Source
offset.h = ffffffff offset.l = b1d4be46
Uniform Adjustment Requested: -305 Milliseconds
This server is configured as a SECONDARY
Sat Feb 10 04:16:37 2007


So...what the h- is going on?! What does "Invalid NTP Stratum" mean?
This happened in the middle of the night, so we're not doing any work on
the server when this happened.

I can get time to sync back correctly by unloading and reloading
timesync on Server_B...but then it's only a matter of time before time
drifts off again.

Any ideas? Thanx in advance.

Howard