Multiple distributed switches with same vlans?

[MGK201110141]

Isn't it possible to have several distributed switches with the same vlans?

when I try to create another switch and add my vlan with same name as before I get an error message that it allready exists.

[RichardBush]

Yes you can, however the name needs to be Unique.

So you cant have 3 portgroups with the name Vlan1, with vlan 1 tagged. But you could have 3 PortGroups called Vlan1-A, Vlan1-B, Vlan1-C all tagging vlan 1.

Rich

[MGK201110141]

strange that you have to have unique name.

that complicates alot. try vmotion from one host to another host that uses the same vlan but have two different distributed switches.

You would have to use webclient and have to match src and dst network. It's quite awful experience

In the same scenario as the above, you could have two standard switches with the same network name. when you vmotion it all is next next.

[RichardBush]

Sorry i think you ve lost me here, a VDS can span multiple hosts and a standard switch is defined on a single host, is that the confusion here ? Could you explain in more detail.

But you can't have the same network name on two standard switches either.

When you are Vmotioning between hosts you expect the VDS to be across the hosts in the cluster, or yes you would have to change the destination VDS if it didnt exist on the destination host.

Rich

[MGK201110141]

You can on standard switch. two different hosts with their own standard switch. no problem having same name on network with same vlanid.

Host1:

Standardswitch (vswitch0):

Networkname: internalnetwork -> vlanid1

Host2:

Standardswitch (vswitch0):

Networkname: internalnetwork -> vlanid1

        

No problem vmotioning between host1 and host2. No need to redefine network on vmotion.

But if I create two distributed switches, i seem to need to have different names on the network.

Host1:

distributedswitch1 (uplinkports attached to host1):

Networkname: internalnetwork1 -> vlanid1

Host2:

Distributedswitch2(uplinkports attached to host2):

Networkname: internalnetwork2 -> vlanid1

Vmotion between host1 and host2 needs webclient and we need to redefine network src and dst, because it's different names.

Host1 and host2 is the example is in two different clusters. I understand that distributed switch can span over multiple hosts(that's why I want to use it), but I don't understand why naming can't be the same on two distributed switches. is it because a host can have two distributed switches attached  on different uplinks? because if you got only got one distributed switch on one host and a different distributed switch on another one, I really can't understand why there is a limitation of naming.

[RichardBush]

‌ok yes, as you say  it's possible to have the same name on different hosts on the standard switch, I thought you were trying to place the 2  on the same host.

That explination puts it more in context.

Are the DVS in your setup in different clusters? I can't test this on my dev rig. If so I am surprised you can't have the same name in different clusters. At which point is guess it's a limitation of the vcenter server only allowing one instance of the PG name, but I'd have thought this would be useful for cross cluster migrations.

RIch.