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