[j-nsp] Windows NTP server for JUNOS client

[abdullahbaheer]

Yes the windows server wasn't in synch with it's parent
After fixing that, issued a set date and it is fixed.

Thank you all for your help


Sent from Samsung Mobile

-------- Original message --------
From: Jared Gull <jmgull at yahoo.com> 
Date: 24/07/2013  4:43 PM  (GMT+03:00) 
To: Abdullah Baheer <abdullahbaheer at yahoo.com>,juniper-nsp at puck.nether.net 
Subject: Re: [j-nsp] Windows NTP server for JUNOS client 
 
Hi Abdullah,

I have seen others experience issues when using a Windows server as their NTP server when that server does not have an external time source. Does your Windows NTP server have an upstream time source? If not, you could try to link it with one to see if that fixes the issue. If not, you may need to do some local modifications on the server. As I understand it the issue stems from a high root dispersion value on the WIndows server. You can confirm the root dispersion value by capturing an inbound NTP packet on your Junos device:
 
12:40:22.325750  In
        Juniper PCAP Flags [Ext, no-L2, In], PCAP Extension(s) total length 22
          Device Media Type Extension TLV #3, length 1, value: Ethernet (1)
          Logical Interface Encapsulation Extension TLV #6, length 1, value: Ethernet (14)
          Device Interface Index Extension TLV #1, length 2, value: 132
          Logical Interface Index Extension TLV #4, length 4, value: 365
          Logical Unit Number Extension TLV #5, length 4, value: 511
        -----original packet-----
        PFE proto 2 (ipv4): (tos 0x0, ttl 126, id 28940, offset 0, flags [none], proto: UDP (17), length: 76) 10.11.14.1.123 > 10.13.11.248.123: [udp sum ok] NTPv3, length 48
        Server, Leap indicator:  (0), Stratum 3, poll 9s, precision -6
        Root Delay: 0.000000, Root dispersion: 10.062759, Reference-ID: 202.175.115.244
          Reference Timestamp:  3572566348.629499999
          Originator Timestamp: 3572570422.323693987
          Receive Timestamp:    3572570422.316499999
          Transmit Timestamp:   3572570422.316499999
            Originator - Receive Timestamp:  -0.007193988
            Originator - Transmit Timestamp: -0.007193988
 
If you see the high root dispersion and you are using Windows 2003/2008 server, you can change the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time\Config\LocalClockDispersion from value 10 to value 0 and then restart the time services in the command prompt by “w32tm /config /update”. After that you can then capture the NTP packet again the see that the value has changed and verify the client no synchronizes with the server.

Hope this helps,

Jared

From: Abdullah Baheer <abdullahbaheer at yahoo.com>
To: "juniper-nsp at puck.nether.net" <juniper-nsp at puck.nether.net> 
Sent: Wednesday, July 24, 2013 6:13 AM
Subject: [j-nsp] Windows NTP server for JUNOS client

Hi

Has anyone tried to synchronize NTP from Junos device towards Windows NTP server (NTP running as a service from Windows)?
I am trying and getting the following output:
show ntp associations 
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 192.168.x.x  .LOCL.           1 -    1   64    1    3.438  -13033.  73.051

There is no "*" in the beginning, in stead there is a space, which I checked and it means:
    * space—Discarded because of a high stratum value or failed sanity checks.
My Netscreen devices are able to sync with this NTP server.

Thanks
Abdullah Baheer
_______________________________________________
juniper-nsp mailing list juniper-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp