Re: NTP sync problem

mike.cunningham · ‎03-08-2006

I have one 6500 switch with a sup720 which sucessfully gets time from the Internet. Most of my routers and switches were pointing to 10.210.210.1 as an NTP source. When cutting over to a new circuit the 10.210.210.1 address went away. When I tried to change the address in my NTP client switches they would remain unsynchronized although the address was pingable and I could get NTP from the server with an XP box.

Here is the output from debug ntp packet:

.Mar 8 11:08:02: NTP: xmit packet to 10.1.1.254:

.Mar 8 11:08:02: leap 3, mode 3, version 3, stratum 0, ppoll 64

.Mar 8 11:08:02: rtdel 0A0D (39.261), rtdsp 0F38 (59.448), refid 0AD2D201 (10.210.210.1)

.Mar 8 11:08:02: ref C7945231.78A7DF69 (06:19:13.471 est Wed Feb 8 2006)

.Mar 8 11:08:02: org 00000000.00000000 (19:00:00.000 est Thu Dec 31 1899)

.Mar 8 11:08:02: rec 00000000.00000000 (19:00:00.000 est Thu Dec 31 1899)

.Mar 8 11:08:02: xmt C7B97FE2.41CA0EA2 (11:08:02.256 est Wed Mar 8 2006)

Does the reference to 10.210.210.1 in the debug mean that it is still trying for that address?

I have one 6500 switch which CAN get NTP from 10.1.1.254. I created a loopback address of 10.210.210.1 and everyone started getting NTP time. Am I locked into that address for some reason?

nethelper · ‎03-08-2006

Hallo,

looking at this line in your output:

Mar 8 11:08:02: leap 3, mode 3, version 3, stratum 0, ppoll 64

it looks like 10.1.1.254 is a stratum 0 device, which means that it cannot serve as a time source for Cisco devices. Then again, you say that your 6500 can get time from that device. What exactly is 10.1.1.254 ? Would it be possible to reboot one of your devices and check if the sync occurs after that ?

Regards,

Nethelper

mike.cunningham · ‎03-08-2006

10.1.1.254 is a stratum 3 device and is a 6500 with a sup720 running native mode. It is getting time from the Internet.

I am not sure if this is relevent but the only devices which can get time from it are three switches connected over dot1q pagp trunks. I will try to boot one of the non working clients overnight.