Windows server 2016 Hyper-V external Switch really slow speed

Eduard Martinenko 106 Reputation points
2020-09-08T10:33:23.85+00:00

I have a windows server 2016 machine, with two network interfaces, and installed Hyper-V server.
I want my virtual machines to be accessible from the external network (Local restricted network, without internet) and make it so that my virtual machines could get an IP address from the external DHCP server.

So I created a new external switch and made a network bridge between my real network card and the "virtual" hyper-v switch.

It works, but the speed is just abysmal... And the strangest thing not always. Sometimes it could be the full speed, sometimes especially when copying a large file between two virtual machines speed can reach as low as 10-15Kbyte/sec for no apparent reason (the network itself is more than capable to handle such load )).
When using the "internal" switch all work just fine without any problems.

What is the usual reason for this problem?

Maybe I don't need to create a bridge? (but how will my virtual machines be accessible from the network?)

Hyper-V
Hyper-V
A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
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  1. Dave Patrick 426K Reputation points MVP
    2020-09-08T12:40:54.733+00:00

    Maybe I don't need to create a bridge?

    That's correct. When you create a new external vSwitch the internet protocols are removed from the adapter and the Hyper-V Extensible Switch protocol is added turning that physical port into a multi-port virtual switch. Connect your VMs to this vSwitch and use each VM's vEthernet to configure the addressing in the exact same manner as if it were a physical NIC

    --please don't forget to Accept as answer if the reply is helpful--

    1 person found this answer helpful.
  2. Dave Patrick 426K Reputation points MVP
    2020-09-09T13:59:36.943+00:00

    https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/quick-start/connect-to-network

    There's nothing extra for the end user to do, I'd suggest deleting / recreating the vSwitch. When you create a new external vSwitch the internet protocols are removed from the adapter and the Hyper-V Extensible Switch protocol is added turning that physical port into a multi-port virtual switch. Connect your VMs to this switch.

    --please don't forget to Accept as answer if the reply is helpful--