Saturday, January 26, 2008

Network Time Protocol NTP on Windows 2003 Servers and Cisco Routers.

Starting in the spring of 2007, daylight saving time (DST) start and end dates for the United States will transition to comply with the Energy Policy Act of 2005. DST dates in the United States will start three weeks earlier, at 2:00 A.M. on the second Sunday in March. DST will end one week later, at 2:00 A.M. on the first Sunday in November. This has caused a lot of issues on unpatched machines and routers.

Here is an article about the issue:
http://support.microsoft.com/kb/931836

The latest patch for Microsoft servers:
http://support.microsoft.com/kb/933360/

Configuration of time servers is extremely important, everything from your applications to your network devices all depend on proper time synchronization. This blog breifly discusses the configuration of NTP for Windows 2003 servers and cisco routers. I usually sync the routers and the DC to a public NTP Server. For some reason, the cisco routers have a hard time syncing with Windows 2003 NTP Servers.

Time servers

  • clock.isc.org
    204.152.184.72
  • Saskatchewan, Canada: University of Regina
    142.3.100.15
    timelord.uregina.ca
    Service Area: Canada
  • Ontario, Canada: National Research Council of Canada
    132.246.168.148, 132.246.168.164
    time.chu.nrc.ca;
    time.nrc.ca
    Service Area: Canada

Windows Time Server Configuration

Check the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer

http://support.microsoft.com/kb/816042

Configuration of Cisco router

ntp server 204.152.184.72 prefer
ntp server 142.3.100.15
ntp server 132.246.168.148

Make sure the firewall rules are off when you are configuring your router.

Network Time Server URL:
http://support.microsoft.com/kb/262680

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