how to fix VSP 8600 NTP Master ?

[ytlee]

Currently I am setting up NTP with two vsp8600 series. The vsp8600 works well with the ntp server, but it seems that it is not working with the ntp master. Even though I entered the "ntp master" command, if I do "ntp server VSP" in Cisco s/w, the sync does not work. How can I fix it? For reference, the version is 8.0.1

[Ludovico_Steven · Accepted solution]

The ntp master/restrict options only work with NTPv4 on VOSS.

You can see it if you do “show ntp” on the 8600, note the associated NTP version.

VSP8600-1:1(config)#% show ntp
====================================================================================================
                                   NTP Master
====================================================================================================
Version   Enabled        Stratum
----------------------------------------------------------------------------------------------------
4         False          10

====================================================================================================
                                   NTP Client
====================================================================================================
Version   Enabled        Interval    Last Update Time                   Synchronized To
----------------------------------------------------------------------------------------------------
3         True           15          Mon Mar 22 09:37:27 2021 UTC       10.8.255.160 (Stratum:3)

And on VOSS & VSP8600 NTPv4 is only supported on the Segmented Mgmt Interfaces.

But while VOSS VSPs have fully transitioned to only Segmented Mgmt as of 8.2.0.0, the VSP8600 is still in a transition phase where you can enable Segmented Mgmt IPs for NTPv4 support, but don’t have to for all other switch management protocols which can still run on any IP interface you create in GRT (VRF-0).

So I suspect that NTP Client is working for you, but in NTPv3 not NTPv4.

Long story short, if you want to make use of NTP Master, you will need to flip NTP to version 4. To do that you will have to create/allocate an IP CLIP under the Segmented Mgmt Interface, using these commands:

VSP8600-1:1(config)#% mgmt ?
  clip  Loopback interface
VSP8600-1:1(config)#% mgmt clip ?
  vrf  Vrf configuration
  <cr>

Then change the NTP version from 3 to 4.

Now this new IP will be used as NTPv4 Client and you can point your Ciscos to it for the NTP Master functionality.