BladeSystem Virtual Connect
Showing results for 
Search instead for 
Did you mean: 

Tunnel mode, NIC teaming, Windows - same MAC on all NICs

Trusted Contributor

Tunnel mode, NIC teaming, Windows - same MAC on all NICs

Michael had a customer question:




Hello experts,

A customer is using VC Tunnel mode with a tagged network to support multiple VLANs needed for ESX and  bare-metal WS 2008 in the same enclosure. ESX is a non-issue; works great. The Windows servers use HP NIC Teaming, and a new NIC pair is created for every VLAN. That, too, works fine and system administrators are happy.


The problem is that all the Windows NIC Teams (one for each VLAN) reference the same MAC address. This causes lots of SQL Cluster validation errors as SQL sees multiple NICS with the same MAC. DBAs are not happy, as they say they cannot install SQL server with failed validation tests.


Question: Is there any way in this scenario to have a unique MAC for each VLAN team?  Anyone have a similar scenario and know of a clever workaround?




From Robert:




To my knowledge, there is no way to generate virtual mac addresses from the Network Configuration Utility (NCU).  NCU creates miniport adapters when teams and subsequent vlans are created.  Each Vlan assumes the mac addresses of the physical adapter it is associated with.  This should not cause an issue, as mac duplication is only an issue at layer 2.  As long as the mac addresses are not duplicated in the same broadcast domain, you should be fine.




Any other comments or suggestions on this problem?