Diagnosing a vlan issue on Cisco UCS pre 2.2

New VLAN not attaching to vnic

Added a new vlan to a service profile template and even though it shows in the UCSM UI there was no traffic traversing the vlan.

First you need to know what the vnic id is:

ssh [email protected]

Work out which service profile you are looking at and set your scope to it’s adapter

fc01-A# show service-profile assoc|grep SRV
fc01-A# scope org SOperations/HyperVisors/
fc01-A /org # scope service-profile HyperV01

Get the MAC addresses for your vethernet adapters

fc01-A /org/service-profile # show vnic

Name       Fabric ID Dynamic MAC Addr
———- ——— —————-
eth0       A B       00:25:B5:04:02:6F
eth1       B A       00:25:B5:04:01:4F
fc01-A /org/service-profile # exit
fc01-A /org # exit

Connect to NXOS

fc01-A# connect nxos

Get the Veth adapter id, grep for your vlan id while doing a show vlan

fc01-A(nxos)# show vlan |grep 1196
1196 VLAN1196                         active    Po1, Veth1484, Veth1490
fc01-A(nxos)# show vlan |grep 1197
1196 VLAN1197                         active    Po1, Veth1484
fc01-A(nxos)# show interface vethernet 1484 |grep server
Description: server 1/2, VNIC eth0
fc01-A(nxos)# show interface vethernet 1490 |grep server
Description: server 3/2, VNIC eth0

This will allow you to confirm using show  assoc that the both your servers have the vlan id

fc01-A# show server assoc |grep 1/2
1/2     Associated   HyperV01
fc01-A# show server assoc |grep 3/2
3/2     Associated   HyperV02


As you can see the seconds vlan id (1197) was missing from HyperV02. This is a known bug and luckily these hypervisors are clustered so we can re-ack them. Rebooting will not fix the problem, so you will need to re-acknowledge them in the UCSM server’s interface.