9800-40 adding vlan spontaneous reboots

[lcaruso]

Hi,

I have a pair of 9800-40s running 17.6.4 code in HA SSO Active/Standby Failover VSS With Split Links RMI+RP 

When I add a VLan to the trunk to the VSS core from the 9800 side, the primary spontaneously reboots.

Was not the behavior I expected. Anyone else seen this or know why it happens?

Thanks.

[Scott Fella · Accepted solution]

Your RMI-RP really should be directly connected or should be on a dedicated vlan that is not routed. Seems like when you make a change SSO is failing over because the RP is loosing connectivity.

[lcaruso]

Scott, you may find this interesting. Adding the vlans to the port channel interface on the 9800-40 HA pair instead of to the physical interfaces solved the issue. That idea was provided by Rasika, https://mrncciew.com/

[Scott Fella]

That is interesting as I would have assumed the vlans in the port channel and interface would have the same configuration. Well that would be a reason that the RMI detected the other was not reachable. Good that you figured that out.

[lcaruso]

Truly interesting since training tells you to always add the vlans under the physical interfaces. We checked afterwards and sure enough the changes were propagated down to the physical interfaces after adding at the port channel level.