We have two hosts (6.5 U1) with a quad port NICs that are partitioned to 8 virtual NICS, so for example vmnic0 is the same physical port as vmnic4, vmnic1 is the same as vmnic5, etc. We have a DVS with a port group on our main VLAN (say 200) on vmnic0 and a standard switch also on VLAN 200 on vmnic4 (so same physical port to the switch) on both hosts. I've noticed the following scenario:
VM1 (standard switch) & VM2 (DVS) are on host 1, VM3 (standard switch) & VM4 (DVS) are on host 2
VM1 -> VM2 can't communicate (NOT OK)
VM1 -> VM3 can communicate (OK)
VM1 -> VM4 OK
VM2 -> VM1 NOT OK
VM2 -> VM3 OK
VM2 -> VM4 OK
VM3 -> VM1 OK
VM3 -> VM2 OK
VM3 -> VM4 NOT OK
...
So, VMs on the same host can't communicate between the DVS and standard switch even though they are on the same VLAN & underlying switching hardware. VMs can communicate between hosts no matter whether or not either is on DVS or standard switch. Is this expected behavior? It doesn't make sense to me