NTP Synchronous Problem.

[chaoping chen]

In my network I has a NTP Server running in Windows 2003 OS, the issue I met is any other servers and hosts in the network can sync the time with the NTP server, but all of the Cisco network device can't , such as the pix ,the switch 2950,3560,and the 6500 also.

I have search many doc at the cisco.com. but can find no doc talking about how the Cisco working with the Microsoft, so I find for your help here.

Topic:

   NTP Server---- Outside PIX inside --------- NTP Client(SW2950)  can't work

                                                    ----------NTP Client (Windows) work

Information:

NTPClient#show ntp associations detail 
10.3.255.1 configured, insane, invalid, unsynced, stratum 16
ref ID 0.0.0.0, time 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)
our mode client, peer mode unspec, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 0.00, reach 0, sync dist 0.000
delay 0.00 msec, offset 0.0000 msec, dispersion 16000.00
precision 2**5, version 3
org time D201B679.F0000000 (06:06:49.937 UTC Fri Aug 26 2011)
rcv time AF3BD80F.35EF8634 (00:32:15.210 UTC Mon Mar 1 1993)
xmt time AF3BD80F.343F3A1C (00:32:15.204 UTC Mon Mar 1 1993)
filtdelay =     0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
filtoffset =    0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
filterror =  16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0

Debug ntp packets 
00:36:31: NTP: xmit packet to 10.3.255.1:
00:36:31:  leap 3, mode 3, version 3, stratum 0, ppoll 64
00:36:31:  rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
00:36:31:  ref 00000000.00000000 (08:00:00.000 beijing Mon Jan 1 1900)
00:36:31:  org D201B739.F4000000 (14:10:01.953 beijing Fri Aug 26 2011)
00:36:31:  rec AF3BD8CF.37200D92 (08:35:27.215 beijing Mon Mar 1 1993)
00:36:31:  xmt AF3BD90F.343CB67E (08:36:31.204 beijing Mon Mar 1 1993)
00:36:31: NTP: rcv packet from 10.3.255.1 to 10.1.32.240 on Vlan99:
00:36:31:  leap 0, mode 4, version 3, stratum 2, ppoll 64
00:36:31:  rtdel 0800 (31.250), rtdsp 100000 (16000.000), refid 7F000001 (127.0.0.1)
00:36:31:  ref D2019DE2.CBCED916 (12:21:54.796 beijing Fri Aug 26 2011)
00:36:31:  org AF3BD90F.343CB67E (08:36:31.204 beijing Mon Mar 1 1993)
00:36:31:  rec D201B779.F4000000 (14:11:05.953 beijing Fri Aug 26 2011)
00:36:31:  xmt D201B779.F4000000 (14:11:05.953 beijing Fri Aug 26 2011)
00:36:31:  inp AF3BD90F.365097FF (08:36:31.212 beijing Mon Mar 1 1993)
00:37:35: NTP: xmit packet to 10.3.255.1:
00:37:35:  leap 3, mode 3, version 3, stratum 0, ppoll 64
00:37:35:  rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
00:37:35:  ref 00000000.00000000 (08:00:00.000 beijing Mon Jan 1 1900)
00:37:35:  org D201B779.F4000000 (14:11:05.953 beijing Fri Aug 26 2011)
00:37:35:  rec AF3BD90F.365097FF (08:36:31.212 beijing Mon Mar 1 1993)
00:37:35:  xmt AF3BD94F.343E02D5 (08:37:35.204 beijing Mon Mar 1 1993)
00:37:35: NTP: rcv packet from 10.3.255.1 to 10.1.32.240 on Vlan99:
00:37:35:  leap 0, mode 4, version 3, stratum 2, ppoll 64
00:37:35:  rtdel 0800 (31.250), rtdsp 100000 (16000.000), refid 7F000001 (127.0.0.1)
00:37:35:  ref D2019DE2.CBCED916 (12:21:54.796 beijing Fri Aug 26 2011)
00:37:35:  org AF3BD94F.343E02D5 (08:37:35.204 beijing Mon Mar 1 1993)
00:37:35:  rec D201B7B9.F4000000 (14:12:09.953 beijing Fri Aug 26 2011)
00:37:35:  xmt D201B7B9.F4000000 (14:12:09.953 beijing Fri Aug 26 2011)
00:37:35:  inp AF3BD94F.35F1433B (08:37:35.210 beijing Mon Mar 1 1993)
00:38:39: NTP: xmit packet to 10.3.255.1:
00:38:39:  leap 3, mode 3, version 3, stratum 0, ppoll 64
00:38:39:  rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
00:38:39:  ref 00000000.00000000 (08:00:00.000 beijing Mon Jan 1 1900)
00:38:39:  org D201B7B9.F4000000 (14:12:09.953 beijing Fri Aug 26 2011)
00:38:39:  rec AF3BD94F.35F1433B (08:37:35.210 beijing Mon Mar 1 1993)
00:38:39:  xmt AF3BD98F.343C3CAA (08:38:39.204 beijing Mon Mar 1 1993)
00:38:39: NTP: rcv packet from 10.3.255.1 to 10.1.32.240 on Vlan99:
00:38:39:  leap 0, mode 4, version 3, stratum 2, ppoll 64
00:38:39:  rtdel 0800 (31.250), rtdsp 100000 (16000.000), refid 7F000001 (127.0.0.1)
00:38:39:  ref D2019DE2.CBCED916 (12:21:54.796 beijing Fri Aug 26 2011)
00:38:39:  org AF3BD98F.343C3CAA (08:38:39.204 beijing Mon Mar 1 1993)
00:38:39:  rec D201B7F9.F4000000 (14:13:13.953 beijing Fri Aug 26 2011)
00:38:39:  xmt D201B7F9.F4000000 (14:13:13.953 beijing Fri Aug 26 2011)
00:38:39:  inp AF3BD98F.35EFDF0A (08:38:39.210 beijing Mon Mar 1 1993)

Configuration
clock timezone GMT 8
ntp server 10.3.255.1 source Vlan99

NTPClient#show ntp status 
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18
reference time is 00000000.00000000 (08:00:00.000 beijing Mon Jan 1 1900)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.00 msec, peer dispersion is 0.00 msec

消息编辑者为：chaoping chen

[ngoldwat · Accepted solution]

Hi,

It appears that some IOS devices that contain NTP cannot sync to an SNTP server such as the prevalent Windows w32time service.  Please see http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCed13703

'show ntp associations detail" will show that the server is
flagged as "insane, invalid".  The "root dispersion" value
will be seen as being in excess of 1000 ms, which will cause
the IOS NTP implementation to reject the association.

Workaround: instead of running the w32time service on the
Windows system, use NTP 4.x - see
http://www.eecis.udel.edu/~mills/ntp/html/hints/winnt.html

Thanks