A Question on VM network traffic through a virtual switch

[Phoung]

I have a question please. I though I read somewhere that if you have 2 VMs on the same ESXi host and they are on the same VLAN, when those VMs want to talk to each other they do not leave the ESXi host through the physical network cards.

I now read in the documentation that is only correct if the Virtual Network they are on does not have a physical Network Card attached. In other words you create an Uplink/Port Group without a physical network card attached.

So since I am using a Distributed Switch and say I have a Port Group named Phoung(VLAN 2) that has a Physical Network Card attached. Now I have 2 VMs on the same ESXi host on that VLAN and when they talk to each other will the traffic stay in the ESXi host, or will it still go out the physical network card to the network and come back.

Reading different documents about this has me a bit confused. I thank you.

[a_p_ · Accepted solution]

Where did you read that the traffic will leave the virtual switch?

Unless I'm missing something the traffic only leaves the host if either the VM's are on different subnets (i.e. require routing), or if they are on different virtual switches.

André

[Phoung]

I believe I am mistaken. I found this which seems to answer my question. This applies to Distributed Switch too?

Understand How Virtual Machine Traffic Routes

I am thankful for your response.

[rcporto]

This applies to Distributed Switch too?

Yes.