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Rich Marsh
Occasional Visitor


Hi Everyone,

I could really do with some help on this one, I have two ESX4 hosts, they have many nics, but two that manage the LAN port groups for my Virtual machines. I have setup port groups on vlan 2, 3 and4 on both ESX hosts and placed virtual machines in those port groups as per below.

vmachine1 (HOST1) PortGroup VLAN2
vmachine2 (HOST1) PortGroup VLAN3
vmachine3 (HOST1) PortGroup VLAN4

vmachineA (HOST1) PortGroup VLAN2
vmachineB (HOST1) PortGroup VLAN3
vmachineC (HOST1) PortGroup VLAN4

The problem I have is that vmachine1 cannot see vmachineA, nor can vmachine2 see vmachineB..and you get the idea.

I thought that on my HP2510G-48 i would need to make a trunk, and add the 2 nics from each ESX host into that trunk, so that the VLAN tagged traffic could be passed, but this doesnt work. So then I made a vlan (VLAN2) on the switch and included the nics from the hosts as 'untagged' into that VLAN2. The Vmachines still cannot see each other. I have read millions of pages online and eventually i got the vmachines to see each other by taking the ESX nics out of the default vlan and adding them as 'untagged' in the VLAN2. But I can only mark those ESX nics as 'untaged' in one vlan, which is not what i need, I need those nics to pass traffic for all those vlans.

My understanding that i need to mark a port on the switch untagged to get it to be in that vlan. I have tried everything, and cannot get this working, I am not sure if the ESX nics need to be trunked and left, trunked and then put that trunk into a vlan or some other variation....

GVRP is another feature i have enabled but i dont think i need.

Any help would be very much appreciated, the literature doesn't seem to clear on this.

Any questions or ideas, come back to me.


Occasional Advisor

Re: ESX 4 - HP 2510G-48 & VLANS -PLEASE HELP

Hi Rich,

I've not done this myself and I'm sure someone will follow-up with better information, but this may help until they do.
Looking at the following white paper,


You do need to have the trunk port as 802.1q tagged and in the correct VLAN.
Create the trunk, create the VLAN, then add the trunk to the VLAN as tagged.

Ralf Krause
Frequent Advisor

Re: ESX 4 - HP 2510G-48 & VLANS -PLEASE HELP

Hi Rich,

be careful here with different wording ...

What VMware names a "trunk" differs from what the HP switch defines as a "trunk".

Basically, network jargon differs between:
1. VLAN trunking
--> That's what VMware (and BTW Cisco)
calls a trunk.
This represents VLAN tagging by IEEE 802.1Q.
2. Port Trunking
--> This is link aggregation (what e.g.
Cisco would call "channeling" or
server folks refer to it as "teaming"
or "bonding".

I assume your aproach is setting up a VLAN trunk.

Don't know how to do it on the ESX (but I think the link provided earlier in this thread should help).

On the 2510, the command(s) would be:

(conf)# vlan 2
(conf-vlan)# tag
(conf-vlan)# exit

Repeat this for all of your vlans.

This will result in a link, which has vlans 2 through 4 tagged with vlan 1 untagged (sometimes referred to as "native vlan").