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ntp server error

jsaezjim1
Level 1
Level 1

I am trying to syncronice my pc to a ntp server, but the "debug ntp" show:

Feb 15 18:24:46.448: NTP: packet from 10.10.10.1 failed validity tests 64
Feb 15 18:24:46.448: Peer/Server Clock unsynchronized
Feb 15 18:24:46.448: Peer/Server Stratum out of bound

NTP configuration is:

ntp clock-period 17182124
ntp source Vlan901
ntp master 4
ntp update-calendar
ntp server X.X.X.X  (a real ntp server)

Why?

Thanks.

1 Accepted Solution

Accepted Solutions

This doesn't appear to be a capture of traffic between the router in question and the client.  This capture looks good.  Time is being properly synchronized.

View solution in original post

9 Replies 9

Joe Clarke
Cisco Employee
Cisco Employee

Your peer's stratum is greater than 4.  Make sure you're NTP server peer has a stratum less that your desired stratum of 4, and the clock should synchronize.

My Cisco synchronize ok with its ntp server (it´s stratum 2). The problem is other: i need that all servers in my company synchronize with my Cisco. I explain: i need that a pc synchonize with a Cisco Router, and this Cisco Router syncrhonize with other ntp server. The Cisco Router synchonize ok, but  pcs not.

Cisco Router Configuration:

ntp clock-period 17183677
ntp source Vlan901
ntp master 4
ntp update-calendar
ntp server x.x.x.x (it's ntp server)

is this configuration wrong?

thanks

Are you sure your PCs can access the router on udp/123?  That is, if you start a sniffer trace on one of your clients filtering on udp/123 traffic, what do you see?

My Pc access the router on udp/123 and synchronize, but he "debug ntp" on Cisco router is:

Feb 15 18:24:46.448: NTP: packet from 10.10.10.1 failed validity tests 64               (10.10.10.1 is my pc)
Feb 15 18:24:46.448: Peer/Server Clock unsynchronized
Feb 15 18:24:46.448: Peer/Server Stratum out of bound

Is it normal?

Thanks

Post the output of "show ntp stat" from this router.  What version of IOS is it running?

#      show ntp status

Clock is synchronized, stratum 3, reference is 10.252.120.5

nominal freq is 250.0000 Hz, actual freq is 249.8740 Hz, precision is 2**24

reference time is CF27CB30.BFBE78D8 (15:20:32.749 GMT Thu Feb 18 2010)

clock offset is 5.7081 msec, root delay is 5.91 msec

root dispersion is 33.17 msec, peer dispersion is 4.71 msec

Version 12.2(17r)SX5, RELEASE SOFTWARE (fc1)

what operatings system does the PC have ? What does the NTP configuration looks like on the PC?
The debug message sounds a bit like your PC wants to update the router and the packet is rejected... (because your PC is unsynchronized...)

have you tried the packet capture jclarke suggested? If yes, could you post the capture here?

OS is Windows XP and synchronize well, but the debug on the router show "unsynchronize". The capture on my pc (I attach it) show that my pc synchronize to other router.

This doesn't appear to be a capture of traffic between the router in question and the client.  This capture looks good.  Time is being properly synchronized.

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