Duplicate vNIC on VMs after restore from backup

At present, I’m involved in a project for a client to migrate virtual machines (VM) from one data centre in Ireland to another in Continental Europe.

I encountered an issue after backing up the VM and restoring it in the new DC with NetBackup.

Once the VM was restored, registered in vCenter and powered on, I needed to re-IP the VM. I saw that I had no IP connectivity (Couldn’t ping, RDP, etc). After some initial troubleshooting I found that the Windows Server 2008 R2 Network and Sharing Center was reporting two active connections (Though the VM had one NIC) and to confirm the one NIC; Network Connections only showed a single network adapter. Both Windows Device Manager and VM settings show a single vNIC device available.

vNIC

but the default route was showing another connection:

dw_bug

I had come across this issue before in another context, and the following resolved the issue:

From the command prompt run:

set devmgr_show_nonpresent_devices=1

 

Then open Device Manager and select:

View-->Show hidden devices

 

hidden-devices
And then select Network adaptors and delete *(Uninstall) ALL Ethernet Adapters including any greyed out.

after the delete, select:

 

Action-->Scan for hardware changes

 

hardware-changes

You should be left with a single vNIC (Or as many vNIC as you have assigned to the VM)
In the Command Prompt issue the following command to set the default IP/route.

 netsh interface ip set address "Local Area Connection" static IP_Address Subnet_Mask Default_Gateway 

So, for example:

netsh interface ip set address "Local Area Connection 2" 10.100.3.17 255.255.255.0 10.100.3.1

Re-IP any other NICs you have assigned to the VM and connectivity should now be restored!

If this has not resolved the issue, I would recommend opening a support ticket with Microsoft and/or VMware

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