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 <[email protected]> To: "[email protected]" <[email protected]> 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 [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
