UCS-SPL-5108-AC2 - VMs in VLAN Cannot Ping Default Gateway

[Quintin.Mayo]

Hi,

I'm having an issue with the network configuration on the UCS chassis and not sure how to correct. Vnic0 has all the correct vlans and is associated with the template for Fab_A, Vnic 1 is missing vlans and is associated with Template Fab_B. Both templates have all the vlans listed but for some reason it is not being pushed all the way through to the hosts. Any VM on host #3 that is within Network PGD_45 (vlan 45) is unable to ping the default gateway within that vlan, while if you migrate the VM to any other host there is no issue. Each host has the exact same template "CLS_ESX".  I have attached the image for the vlan setup for review. Any help or suggestion would be greatly appreciated. 

[Kirk J]

Greetings.

Please check the CDP information on the Esxi VMNIC information for the impacted NICs.

This should show whether is is A or B side, and the vethernet number.

Take the veth number and check the running config for it from the UCSM CLI :

#connect nxos

nxos#show int vethxxxx

nxos#show run int vethxxxx

This will show the programmed vlans.

Also please check the MAC address listed for the veth, and make sure it is actually the same as the MAC address reported for the VMNIC in ESXi.

We see many cases were ESXi has reordered the VMNIC numbering, and the vnic to VMNIC association is not what you think it is.

You should also check the mac address table on both FIs for vlan in question, to see if you are learning the MAC for GUESTVMs on vlan in question.

Thanks,

Kirk...

[Niko Nikas]

Quintin,

For the template issue (VLANs not pushing to vNIC built off of the template), do you know if the B-side template is an initial template? This might cause the behavior you are reporting.

--

Niko