Changing the VLAN Tag for an Existing ESX Service Console
Once you have made network changes (802.1Q) and you have lost (oops) connectivity to your service console, use the following to change the VLAN tag:
esxcfg-vswitch vSwitch0 -v N -p "Service Console"
Where N is the VLAN tag you want to use. In this case it was vSwitch with the portgroup name "Service Console".
To list the current configuration use: