Thursday, May 3, 2018
Hyper-V SET and NLB in Guest, Duplicate Frames/Packets
Just a quick blurb about switch embedded teaming and Microsoft network load balancing in guest virtual machines. If you've got NLB setup in multicast operational mode running in a VM on top of a Hyper-V host that has SET configured, your VM will receive duplicate frames/packets. It would appear that all the NICs in the SET receive the data and pass it up the network stack. If your upper layer network protocols handle duplicat packets you don't necessarily have to worry about it. ICMP ping for example does not and you will receive multiple responses from your VM. For NLB I would abondon SET and use active/passive NIC teaming.