Quick question on Hyper-V network routing for VMs on the same host in a cluster. RRS feed

  • Question

  • Quick question on Hyper-V network routing for VMs on the same host in a cluster.



    2x Hyper-V Hosts in a cluster.

    2 x Hyper-V Virtual Machines : A & B both on the same hyper-V host


    When Server A communicates with Server B does the network traffic go out of the server to a switch and back in or does the traffic not leave the host.  If it is handled internally by Hyper V is it possibly to say what speed they are communicating at e.g. 1Gb or 10Gb?

    I know the VM shows a 10GB virtual NIC but what speed does it connect to another VM on the same virtual switch if both VMs are on the same host in a cluster?


    Kind Regards

    Michael Coutanche

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    Tuesday, August 2, 2016 4:11 PM


  • Hyper-V Virtual Switches function just like any physical switch.

    If the two ports (vNICs) are on that switch, then no traffic leaves that switch.

    If the route to one of the VMs is out the External Port (physical NIC) of the virtual NIC, then the traffic is routed out.

    A Virtual Switch is represented to VMs as being 10Gb.

    If the traffic leaves the physical Hyper-V Server, the smallest soda straw is the choke point (the physical NIC).  There is no magic that masks that just because the Hyper-V Servers are members of a cluster.

    Clustering enables high availability of virtual machines, it does not cause a virtual switch to span hosts.

    Brian Ehlert
    Learn. Apply. Repeat.

    Tuesday, August 2, 2016 8:50 PM