[SOLVED] Networking issue, (Proxmox on a hyper-v guest)

[eclipsta]

Hello,

As a new user of Proxmox, I've installed it on a virtual machine running on a Hyper-V server (with the goal of exploring Proxmox and potentially migrating my server fleet to Proxmox in the future).

I'm having difficulty setting up VMs (tested with Windows 11 and Debian 12) because I can't seem to connect them to the internet using the vmbr0 bridge.

From what I understand, I'm supposed to connect my interface/bridge vmbr0, which has an IP of 192.168.1.36, and this interface is connected to my eth0 interface which has internet access.

After going through the documentation, I'm really not sure why I'm not getting internet connectivity on the Proxmox VMs.

I'll provide you with images of my configuration for reference.

Thank you in advance for any assistance; I would greatly appreciate it.

 

[eclipsta]

Strange setup to have, (I doubt many will have the setup that you have) but first things first.
Can your Proxmox host access the Internet?

Thank you for your response.

This setup is temporary; it's solely for testing Proxmox. If Proxmox proves capable of everything I need, I'll migrate my server fleet to have a single Proxmox server hosting all my different machines.

Yes, Proxmox has internet access; for instance, it can ping 8.8.8.8 (google.com), and I can access the manager at https://192.168.1.36:8006/.

 

[GastonJ]

Sorry deleted my last question since 8.8.8.8 is google

Can you ping 192.168.1.1 - your router from a VM?

 

[eclipsta]

Sorry deleted my last question since 8.8.8.8 is google

Can you ping 192.168.1.1 - your router from a VM?

Yes, i can.

 

[GastonJ]

My settings within the default network in HyperV (virtual switch manager)

Did you tick the Allow management operating system to share this network adaptor?

 

[eclipsta]

Thank you for your prompt response.

Yes, I have allowed the system to share this connection.

 

[GastonJ]

I had thought that maybe your WIndows HyperVM switch may be getting in the way, but it doesn't look as though it is. What message do you get when you try a ping a domain from inside DebVM? Try www.yahoo.com since for some reason they allow ICMP pings
Could also try a traceroute from inside DebVM

 

[eclipsta]

I had thought that maybe your WIndows HyperVM switch may be getting in the way, but it doesn't look as though it is. What message do you get when you try a ping a domain from inside DebVM? Try www.yahoo.com since for some reason they allow ICMP pings
Could also try a traceroute from inside DebVM

Thank you for the response.

I can't even open a shell with all the capabilities of Debian or Windows because I can't complete the installation process due to a lack of any connection access.

However, when opening a shell from the Debian ISO, the ping attempt results in "network unreachable."

 

[GastonJ]

I was wondering whether your DHCP server (if you use one) is refusing to assign an IP address to DebVM - no IP assigned no access to the Internet and so on. Other than that thought I have no more help that I can give. Would like to know the reason if you do get it resolved though.
Cheers

 

[eclipsta]

I was wondering whether your DHCP server (if you use one) is refusing to assign an IP address to DebVM - no IP assigned no access to the Internet and so on. Other than that thought I have no more help that I can give. Would like to know the reason if you do get it resolved though.
Cheers

I also tried to manually assign an IP during the Debian 12 installation process, but it didn't work.

After further research, I came across a forum where someone attempted the same thing as me and encountered the exact same issue, without a solution. It's indeed possible that this could be a flawed implementation on the part of Hyper-V regarding support for Unix systems.

https://www.reddit.com/r/HyperV/comments/pewr26/how_can_i_run_proxmox_on_hyper_v/

I think I'll just get another server and test Proxmox on it (to avoid having two layers of virtualization).

Thank you for the time you spent trying to help me, and I will keep you updated if I happen to find a solution by pure chance.

I remain open to any other potential solutions if someone has managed to address this issue.

 

[eclipsta]

I was wondering whether your DHCP server (if you use one) is refusing to assign an IP address to DebVM - no IP assigned no access to the Internet and so on. Other than that thought I have no more help that I can give. Would like to know the reason if you do get it resolved though.
Cheers

Hello,

After conducting further research, I discovered that enabling "enable MAC address spoofing" resolves the issue. Proxmox is now working well on my Hyper-V server and is capable of providing bridged internet to my main network for guest VMs of Proxmox.

So, for anyone interested in running Proxmox from a Hyper-V guest:

• You need to enable nested virtualization (use this command in Admin PowerShell):
  Set-VMProcessor -VMName 'vmname' -ExposeVirtualizationExtensions $true
• Enable MAC address spoofing on the internet adapter from Hyper-V settings of guest machine.

 

[Surmoon]

Hello,

After conducting further research, I discovered that enabling "enable MAC address spoofing" resolves the issue. Proxmox is now working well on my Hyper-V server and is capable of providing bridged internet to my main network for guest VMs of Proxmox.

So, for anyone interested in running Proxmox from a Hyper-V guest:

• You need to enable nested virtualization (use this command in Admin PowerShell):
  Set-VMProcessor -VMName 'vmname' -ExposeVirtualizationExtensions $true
• Enable MAC address spoofing on the internet adapter from Hyper-V settings of guest machine.

Thanks a lot for this, and for writing the solution here, you solved my head hitting a wall for a day or two !

In my case, Enabling MAC Address Spoofing in the Hyper-V machine settings did the trick. This configuration is very hidden, and you must expand the LAN details (it has an almost negligible "+" sign on the left of your Network adapter that you must click to expand the section, then you'll see the "Advanced Configuration" and there you'll find the checkbox you need to click.

I hope the screenshot helps (sorry, it's in Spanish but I added notes on it to clarify the steps). Basically, you need to CHECK the tick on step 3.

 

[SargOn]

Any way to setup this (mac spoofing) in WSL2... ?

TIA !!