vNetwork Distributed Switch VLAN network failures due to vmnic hardware VLAN

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• An ESX/ESXi 4.0 Update 2 host loses network connectivity after it is restarted
• This issue occurs when the host is using a vDS switch configured with Intel 10GB uplinks
• This issue occurs when using VLAN
• This issue does not occur with a standard switch
• When you pin the vmnic to another port, it works properly

Environment

VMware ESX 4.0.x
VMware ESXi 4.0.x Installable
VMware ESXi 4.0.x Embedded

Resolution

In ESX/ESXi 4.0 Update 2, this issue occurs if a pointer to the VLAN bit map is assigned a wrong value when VLAN RX hardware capability is activated. As a result, the VLAN bit map with an incorrect value is passed to the device driver. For cards which take advantage of VLAN filter function, a wrong VLAN ID is set and the uplink loses external connectivity.

To resolve this issue, you can either apply the ESX/ESXi 4.0 patch or upgrade to ESX/ESXi 4.1.

To apply the ESX/ESXi 4.0 patch, see:

• VMware ESX 4.0, Patch ESX400-201009401-SG: Updates VMkernel, CIM, Scripts, VMware Tools, VMklinux, and VMX (1023759)
• VMware ESXi 4.0, Patch ESXi400-201009401-BG: Updates Firmware (1023768)

To download ESX/ESXi 4.1, see the VMware Download Center.

To workaround this issue and restore connectivity until the next reboot:

1. Remove the uplink from the vDS with the command:
   
   esxcfg-vswitch -Q <vmnic> -V <dvPort ID of vmnic> <dvSwitch> #unlink a vDS uplink
   
   
2. Re-add the uplink with the command:
   
   esxcfg-vswitch -P <vmnic> -V <unused dvPort ID> <dvSwitch> #add a vDS uplink