NTP issue

mohammedrafiq · ‎07-04-2007

Hi,

I am having issue with one of my switch to sync with ntp server.all other switches has been configured same and working fine except this, any idea ?

Regards,

Debug result

.Jul 4 13:33:02 BST: NTP: xmit packet to 10.194.255.2:

.Jul 4 13:33:02 BST: leap 3, mode 3, version 3, stratum 0, ppoll 64

.Jul 4 13:33:02 BST: rtdel 02F8 (11.597), rtdsp 00CF (3.159), refid 0AC2FF02 (10.194.255.2)

.Jul 4 13:33:02 BST: ref C92396F2.2D1DE7BD (07:46:58.176 GMT Fri Dec 8 2006)

.Jul 4 13:33:02 BST: org 00000000.00000000 (00:00:00.000 GMT Mon Jan 1 1900)

.Jul 4 13:33:02 BST: rec 00000000.00000000 (00:00:00.000 GMT Mon Jan 1 1900)

.Jul 4 13:33:02 BST: xmt CA3611FE.16F61BF1 (13:33:02.089 BST Wed Jul 4 2007)

6506-1(config)#

6506-1#sh run | b ntp

ntp clock-period 17179865

ntp server 10.194.255.2

ntp server 10.194.255.1#

6506-1#ping 10.194.255.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.194.255.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/10/12 ms

K2-6506-1#ping 10.194.255.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.194.255.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/11/12 ms

6506-1#

6506-1#sh ntp status

Clock is unsynchronized, stratum 16, no reference clock

nominal freq is 250.0000 Hz, actual freq is 249.9983 Hz, precision is 2**18

reference time is C92396F2.2D1DE7BD (07:46:58.176 GMT Fri Dec 8 2006)

clock offset is 1.3448 msec, root delay is 11.60 msec

root dispersion is 3.14 msec, peer dispersion is 0.87 msec

Richard Burts · ‎07-04-2007

Mohammed

I can think of several things that might cause they symptoms that you describe. The first thing would be problems with IP connectivity. But your successful ping would seem to show proper IP connectivity. It might be possible that the NTP server is configured with access lists that limit the sources to which it will respond. Can you check whether this might be the case? It might be that there is an access list (perhaps on this 6506 or perhaps somewhere along the data path) that will allow ping packets but does not allow NTP packets? Can you check whether this might be the case?

HTH

Rick

HTH

Rick

mohammedrafiq · ‎07-04-2007

Hi Rick,

I have looked on both pair of 6500, but no access list is configured to stop ntp.it just annyoing!!.

Regards,

Edison Ortiz · ‎07-04-2007

Can you post the show ntp status from the ntp providers along with the portion of the ntp config ?

You can also alter the source of the ntp interface from the ntp client (in this case the 6500 switch) by using the ntp source interface command. Perhaps the ntp packet is being sourced by an interface that does not have reachability to the ntp servers.

mohammedrafiq · ‎07-04-2007

Thanks all,

I have added the command "ntp source loop0" and its start working.

Regards,