NTP issue

SDWorx_2 · ‎11-24-2005

Hi,

I want to setup an NTP-server in Windows2003. I already configured the service through the registry but it seems my routers and switches are not able to synchronise although they receive ntp-packets.

Does anyone have any experience with a 2003 NTP-server?

What I also find quite strange are the refid's in the debug-output??

Thanks in advance,

Jan

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The config:

ntp server x.x.x.x version 2

Switch#sh 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 (00:00:00.000 UTC 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

Switch#sh ntp associations detail

x.x.x.x configured, insane, invalid, stratum 1

ref ID .LOCL., time C7300C9D.395C0C70 (09:55:41.224 UTC Thu Nov 24 2005)

our mode client, peer mode server, our poll intvl 1024, peer poll intvl 1024

root delay 0.00 msec, root disp 10140.24, reach 377, sync dist 10142.715

delay 1.74 msec, offset 389948857617.3377 msec, dispersion 1.60

precision 2**6, version 2

org time C7303891.B95C0C70 (13:03:13.724 UTC Thu Nov 24 2005)

rcv time AFF212D8.1B8B5FBA (05:55:36.107 UTC Sat Jul 17 1993)

xmt time AFF212D8.1B1909D0 (05:55:36.105 UTC Sat Jul 17 1993)

filtdelay = 1.74 1.74 1.74 1.68 1.68 1.63 1.72 1.68

filtoffset = 3899488 3899488 3899488 3899488 3899488 3899488 3899488 3899488

filterror = 0.02 0.03 0.05 0.06 0.08 0.09 0.11 0.12

Switch#sh debug

NTP:

NTP events debugging is on

NTP packets debugging is on

*Jul 17 05:34:30: NTP: xmit packet to x.x.x.x:

*Jul 17 05:34:30: leap 3, mode 3, version 2, stratum 0, ppoll 64

*Jul 17 05:34:30: rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)

*Jul 17 05:34:30: ref 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)

*Jul 17 05:34:30: org 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)

*Jul 17 05:34:30: rec 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)

*Jul 17 05:34:30: xmt AFF20DE6.1ADDA01B (05:34:30.104 UTC Sat Jul 17 1993)

*Jul 17 05:34:30: NTP: rcv packet from x.x.x.x to y.y.y.y on Vlan196:

*Jul 17 05:34:30: leap 0, mode 4, version 3, stratum 1, ppoll 1024

*Jul 17 05:34:30: rtdel 0000 (0.000), rtdsp A2029 (10125.626), refid 4C4F434C (76.79.67.76)

*Jul 17 05:34:30: ref C7300C99.6E554830 (09:55:37.430 UTC Thu Nov 24 2005)

*Jul 17 05:34:30: org AFF20DE6.1ADDA01B (05:34:30.104 UTC Sat Jul 17 1993)

*Jul 17 05:34:30: rec C730339E.8B8462D0 (12:42:06.544 UTC Thu Nov 24 2005)

*Jul 17 05:34:30: xmt C730339E.8B8462D0 (12:42:06.544 UTC Thu Nov 24 2005)

*Jul 17 05:34:30: inp AFF20DE6.1BC2D37B (05:34:30.108 UTC Sat Jul 17 1993)

*Jul 17 05:34:30: NTP: x.x.x.x reachable

*Jul 17 05:34:31: NTP: xmit packet to x.x.x.x:

*Jul 17 05:34:31: leap 3, mode 3, version 2, stratum 0, ppoll 64

*Jul 17 05:34:31: rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)

*Jul 17 05:34:31: ref 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)

*Jul 17 05:34:31: org C730339E.8B8462D0 (12:42:06.544 UTC Thu Nov 24 2005)

*Jul 17 05:34:31: rec AFF20DE6.1BC2D37B (05:34:30.108 UTC Sat Jul 17 1993)

*Jul 17 05:34:31: xmt AFF20DE7.1B056504 (05:34:31.105 UTC Sat Jul 17 1993)

*Jul 17 05:34:31: NTP: rcv packet from x.x.x.x to y.y.y.y on Vlan196:

*Jul 17 05:34:31: leap 0, mode 4, version 3, stratum 1, ppoll 1024

*Jul 17 05:34:31: rtdel 0000 (0.000), rtdsp A2029 (10125.626), refid 4C4F434C (76.79.67.76)

*Jul 17 05:34:31: ref C7300C99.6E721E2A (09:55:37.431 UTC Thu Nov 24 2005)

*Jul 17 05:34:31: org AFF20DE7.1B056504 (05:34:31.105 UTC Sat Jul 17 1993)

*Jul 17 05:34:31: rec C730339F.8BE2C201 (12:42:07.546 UTC Thu Nov 24 2005)

*Jul 17 05:34:31: xmt C730339F.8BE2C201 (12:42:07.546 UTC Thu Nov 24 2005)

*Jul 17 05:34:31: inp AFF20DE7.1B770C77 (05:34:31.107 UTC Sat Jul 17 1993)

...

thomas.chen · ‎11-30-2005

I think that there are no full NTP implementations for the Windows platforms. Windows uses W32time which is actually a SNTP implementations which is not as robust and does not contain all the error checking and control of a full RFC compliant NTP server. You will not be able to get most routers to synch with a Windows based SNTP server. The only routers that can run SNTP

are the 800, 1000, 1600 and 1700. Most of the Catalyst switches also run SNTP and can synch to the Windows SNTP servers. In order to synch the routers, you can use the following source:: NTP public server on the internet.

Certain low-end Cisco devices only support SNTP. SNTP is a simplified, client-only version of NTP. SNTP can only receive the time from NTP servers and cannot be used to provide time services to other systems. SNTP typically provides time within 100 milliseconds of the accurate time. In addition, SNTP does not authenticate traffic, although you can configure extended access lists to provide some protection. An SNTP client is more vulnerable to misbehaving servers than an NTP client and should

only be used in situations where strong authentication is not required