NTP on Cisco Nexus Switch

Details

Configure NTP on Cisco Nexus Switch:

conf t
ntp server <NTP_SERVER_IP> [prefer] use-vrf <VRF_NAME>
ntp peer <ip-address> use-vrf <vrf-name>
ntp source-interface <vlan-name>
ntp logging

Where the "ntp server" creates a client relationship to an upstream NTP server. The "ntp peer" creates a symmentric active peer relationship with each peer acting as a server and client.

And here is an example:

ntp server 10.162.100.20 prefer use-vrf default
ntp server 10.162.100.21 use-vrf default
ntp source-interface Vlan26
ntp logging

 The issue faced on a Nexus is that the "source-interface" must be defined as the switch needs to know which interface to use to reach the NTP peer.

 

Verify by doing: 

show ntp peers
show ntp peer-status
show run ntp
show clock

 Admittedly, it is a bit confusing to use "show ntp peer-status" as a way to get info on ntp servers. But running the command will show an asterisk (*) next to the server being actively used.

Main Menu