Use Windows as an Ethernet switch

Question

Use Windows as an Ethernet switch

SYC 21

I've got a Windows 11 PC running several Hyper-V VMs. There are multiple NICs on the PC, one of which is connected to the router, and I would like to have another NIC to provide a wired connection to my LAN for my other devices, i. e., I would like to turn my PC into an Ethernet switch.

I don't want an extra layer of NAT, so ICS is not an option. Here are my attempts:

Network Bridge, which seemed not compatible with Hyper-V and caused a green (because of Windows Insider) screen.
Open vSwitch for Windows, with both LBFO Teaming (according to the OVS documentation) and SET (as LBFO is deprecated), with which I successfully added the two NICs into a bridge, but no packets are forwarded between the NICs.

I believe this could be achieved with vSwitches, as it is competely feasible on Linux, but I'm stuck. Your help is appreciated.

Answer 1

Dave Patrick 341.2K MVP

A pfsense virtual router may be another option. Also note; that many consumer-grade network adapters do a poor job of hosting an external virtual switch so expect some slowness with whatever you end up doing.

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

Dave Patrick 341.2K Reputation points MVP

2021-11-24T13:47:49.86+00:00

Just checking if there's any progress or updates?

--please don't forget to upvote and Accept as answer if the reply is helpful--
SYC 21 Reputation points

2022-01-05T17:02:48.04+00:00

Sorry for being so late to reply. I was preparing for an exam, after which I completely forgot about this.

I eventually gave up and set up an additional VM just to do networking, and everything worked just fine.

Well, maybe this is supposed to be done only in Windows Server. But still, thank you for helping.
Dave Patrick 341.2K Reputation points MVP

2022-01-05T17:05:40.407+00:00

Glad to hear, you're welcome.

Answer 2

Dave Patrick 341.2K MVP

You can simply add a new external 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.

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

SYC 21 Reputation points

2021-11-23T15:05:24.593+00:00

Sorry for my unclearness. I would like the two physical NICs to behave as if they were connected to the same switch. Using two vSwitches for the two NICs produced two separate networks.
Dave Patrick 341.2K Reputation points MVP

2021-11-23T15:12:19.297+00:00

Not a problem, create two external vSwitches, and connect them to any network as needed.

Using two vSwitches for the two NICs produced two separate networks.

Not sure how you got that. Doesn't work that way here for me.

--please don't forget to upvote and Accept as answer if the reply is helpful--
SYC 21 Reputation points

2021-11-23T15:46:49.717+00:00

If I understand you right, you are suggesting that all external NICs on the same computer are actually connected together?
Dave Patrick 341.2K Reputation points MVP

2021-11-23T15:51:25.587+00:00

No, they're not, but if you plugged them into the switch ports on network then they would be,

--please don't forget to upvote and Accept as answer if the reply is helpful--
SYC 21 Reputation points

2021-11-23T15:59:44.58+00:00

So there's some misunderstanding. The diagram I uploaded just now might better explain. My problem is that, I don't have a hardware switch available, so I'm trying to make my PC behave like a physical switch.
SYC 21 Reputation points

2021-11-23T16:01:57.96+00:00

(Because the router and the modem are in a room far away.)

Answer 3

Dave Patrick 341.2K MVP

Ok, well that has nothing much really to do with hyper-v. As to windows as a router to can create a new separate virtual machine for that purpose.
https://www.dell.com/support/kbdoc/en-us/000118763/configuring-windows-server-2012-r2-as-a-router

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

SYC 21 Reputation points

2021-11-23T16:27:20.213+00:00

Thanks for your help, but I don't really want it to be a router, all I need is a switch. This is really simple to do on Linux with Linux Bridge or OVS, and should be the same on Windows with Network Bridges. The reason why I think this is related to Hyper-V is that the Network Bridge which meets all my requirements perfectly doesn't work well with Hyper-V, while all the other approachs I can think of somewhat involves Hyper-V.
SYC 21 Reputation points

2021-11-23T16:33:28.127+00:00

I actually found that green screen. Although it's in Chinese, all the key information are still understandable.
Dave Patrick 341.2K Reputation points MVP

2021-11-23T16:38:16.673+00:00

The only method to do routing in windows is via RRAS role. Better option for routing is generally to use a layer three device.

--please don't forget to upvote and Accept as answer if the reply is helpful--
SYC 21 Reputation points

2021-11-23T16:59:37.987+00:00

In summary, Windows cannot do layer 2 forwarding between multiple physical and virtual NICs, and the only way to do layer 3 is RRAS, which is only available on Windows Server. Therefore as a home user, the only option is to spend more money to buy a proper switch.
Is that right?

Answer 4

Hello,

I would recommend the next article that follow the process to create the NIC Teaming for a vm Host.

https://learn.microsoft.com/en-us/windows-server/networking/technologies/nic-teaming/create-a-new-nic-team-on-a-host-computer-or-vm

Hope this helps with your query,

------
--If the reply is helpful, please Upvote and Accept as answer--

Use Windows as an Ethernet switch

3 additional answers

Activity