Dot1Q Tagging in the Hypervisor

[visitor68]

Typically, an ESX host is connected to a switch port that is   configured as a trunk. The reason, of course, is that an ESX host has a   bunch of VMs on different VLANs and therefore the hyspervisor tags the   frames...and you know the rest...

In all the years I have been configuring switch ports   that connect to ESX hosts, I have always configured them as trunks.   Theoretically, though, the hypervisor does NOT have to tag the frames   if, say, all the VMs are one only 1 VLAN. Is that correct?  I am  thinking then that EST tagging mode is deployed, in which the physical switch does all the tagging and the hypervisor is configured to have all VMs belong to a port group set to VLAN ID 0. Then the physical switch port can be an access port. But in reality, has anyone ever seen  that? If so, how  often and when was the last time?

As I said, I have never seen this.

Thanks

[SCCisco22]

You are correct. If all the virtual machines are on a single Vlan, the network port could be set up as access port on a single Vlan and tagging is not required. We used this scenario many years ago when we ran 2 lines for each Vlan but now we are using trunk lines and tagging traffic.


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[Steve Fuller]

Duplicate of To tag or not to tag in the Hypervisor.

Regards

[visitor68]

Shahid, in that case of many years ago, how did you handle vmotion? Was it on the same VLAN as the server vNIC or was a separate adapter used on a different one? Thanks

[SCCisco22]

At that time, we were not using vMotion at all.  All our virtual machines were using local storage so vMotion was not possible.  Now we use a EMC VNX SAN.

Shahid