Windows VMs get APIPA IP address with DHCP enabled after updating Cisco UCS hosts with VIC 1300 series physical NICs

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

After updating ESXi, Windows VMs using DHCP to obtain an IP will assign themselves an APIPA (169.254.x.x) address, and will be unable to communicate with anything on the network.

Applying the 'ArpRetryCount' workaround via Registry Editor does not resolve the issue. (False Duplicate IP Address on Microsoft Windows virtual machines on ESXi)

The virtual switch on the host has different vmnics attached than it did before the ESXi update. 

Environment

VMware vSphere ESXi on Cisco UCS

Cause

The vmnic alias list can re-enumerate after the ESXi update, which can cause connectivity issues as the new vmnics might not be attached to an upstream physical switchport that is configured for the vSwitch on the host that is passing it traffic. This is a known issue with older Cisco VIC network cards in UCS environments.

Resolution

This can be resolved by editing the host profile(s) in the UCS Manager: 

Cisco UCS vNIC/vHBA Placement : Issue with desired order in VMware ESXi

You can manually re-enumerate the vmnic alias list to the way it was pre-update (usually by comparing to a host that hasn't been updated yet): 

How VMware ESXi determines the order in which names are assigned to devices

You can also use the new alias given to each vmnic, and use the "Manage Physical Adapters" wizard on each affected virtual switch to assign the correct vmnics to each virtual switch.