I read this KB article:


and this kb article:


CURRENT SETUP: simple "VM Network" nothing fancy. vswitch0 has vlan ID set to none(0), load balancing is set to port ID. On the physical switch, again nothing fancy, untagged ports.

I'd like to setup the existing ports with another VLAN as well as the default/untagged. I can do this on my physical switches by adding the port to a tagged/802.1q vlan id. So the port would have both tagged (on that vlan) and untagged (the default vlan) traffic.

The question I have is how to do it in VMWare properly. Do I create a new network (in Inventory, Networking) as a new vNetwork Distributed Switch? If so, do I choose the 4.1 version?

I guess I'm looking for a walkthrough since the KB articles talk more about the physical switch side than VMWare itself.

BOTTOM LINE: all I want to do is allow a VM to communicate on VLAN id = 12 across the existing physical switch ports that are currently untagged ports to vswitch0.


Create a new Port Group on the vSwitch with VLAN 12 assigned to it in its settings, then configure the physical switch port to act as a trunk carrying the default VLAN and 12 and make the default VLAN the one it's currently using.

The set the appropriate VM's vNIC to use the new Port Group.

You don't need distributed switches or anything complex.

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  • can I leave the physical ports as untagged for all the existing VMs to communicate without 802.1q tags? Or will this require me to make the physical port a true trunk port with all vlans tagged with 802.1q tags? – TheCleaner Aug 8 '12 at 20:39
  • Also, when I add the new port group will it cause any disruption in the virtual switch? I will be doing this during our maintenance window but wanted to know if I should expect a slight network outage or not. – TheCleaner Aug 8 '12 at 20:53
  • Sorry, one more...I'm assuming i have to create this port group on all the hosts individually? I don't see a way to create this "across the cluster". I figure I need this for vmotion/drs to work properly. – TheCleaner Aug 8 '12 at 21:34
  • Sorry, was away, to do any of this the physical switch port must be a trunk, there's no avoiding that unless you want one VLAN per port,nehich you don't. Adding the new port group isn't disruptive but changing the ports to a trunk could easily be. If you use regular vSwitches then you need to create the port group on every machine, if you used Distributed Switches (i.e. you have the Enterprise Plus licence) then you can do it in one go. – Chopper3 Aug 8 '12 at 22:00
  • Just an update...all is well. I found out that with my Enterprise licensing I could create th vDS but couldn't add any hosts to it...so that was the point I realized I had to do it per host. – TheCleaner Aug 12 '12 at 14:26

You can also pursue VGT mode - set the VLAN to 4095 on the port group and then set the VLAN tags on the vhost itself. You'd still need to configure the switchport to accept tagged packets and to assign untagged packets to the appropriate VLAN.

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