NTP Sync for Windows Servers from Cisco Core Switch A and B

[inhamit]

Hi, We want to sync NTP for windows server from core switch. We have core switch A and B and both are connected via fiber and have individual management address and configured as a NTP source. Both core switches are getting sync from the GPS source. Please suggest, which IP I should configure in Windows machine to sync with NTP source to have redundancy for NTP sync? What configuration I should do for NTP syncing?

[Leo Laohoo]

If the servers can successfully ping the IP address of the switch, then "ntp server <SWITCH IP ADDRESS>".

Verify by using the command "sh ntp associations" and an ideal output is when the IP address starts with a "*".

[M02@rt37]

Hello @inhamit,

If you want to configure redundancy for NTP synchronization on your Windows server, you would typically configure multiple NTP servers using the DNS names or IP addresses of the NTP servers, rather than the management IP addresses of your core switches.

w32tm /config /manualpeerlist:"IP_of_Core_Switch_A" /syncfromflags:manual /reliable:yes /update

w32tm /config /manualpeerlist:"IP_of_Core_Switch_B" /syncfromflags:manual /reliable:yes /update

w32tm /resync

Windows machine will attempt to synchronize time with any available server in the list. If one NTP server becomes unreachable or fails, the Windows machine will automatically switch to the other available server for time synchronization.

[inhamit]

Thanks M02@rt37 

you mentioned that we should not use management IP address of core switch as NTP server but in here below: u mentioned the IP address of core switch in w32tm config. Can you please explain more on this?

w32tm /config /manualpeerlist:"IP_of_Core_Switch_A" /syncfromflags:manual /reliable:yes /update

[M02@rt37 · Accepted solution]

Hello @inhamit,

On your CORE Swith A & B you have IP configured for Management - also perhaps Loopback.

Add one of these IP, reachable from you Windows machine.

[inhamit]

Thanks M02@rt37 

you mentioned that we should not use management IP address of core switch as NTP server but in here below: u mentioned the IP address of core switch in w32tm config. Can you please explain more on this?

w32tm /config /manualpeerlist:"IP_of_Core_Switch_A" /syncfromflags:manual /reliable:yes /update