[SOLVED] LXC Container Networking Broken from Hyper-V Configuration Trouble

[verulian]

I've been struggling with a networking issue with LXC containers. Networking works fine on my main Proxmox console, but when I create an LXC container (I've tried making multiple containers with static and DHCP) I can't get it to communicate with the network. I have a very simple configuration, PVE:


And for the Ubuntu 20.04 Container network configuration I have:


When I'm in Ubuntu, `ip addr` shows that the IP is assigned and I can ping PVE via `ping 192.168.1.240`:


But pinging the gateway and 1.1.1.1 fails:


What would be causing containers to not get past the PVE host in this case (I also tried turning off the firewall in case that was interfering)?

 

[oguz]

hi,

can you please post the contents of /etc/network/interfaces on your PVE host?

also ip r inside the container for the routing info

 

[oguz]

are you using nested virtualization? (running PVE in another virtual environment)

see this thread[0] for example. symptoms appear to be the same. if you're using another virtuallization software it could be interfering and you may need to allow mac address spoofing on the guest network interface (could be called 'promiscous' or just mac spoofing)

[0]: https://forum.proxmox.com/threads/no-connection-to-the-network-from-lxc.70330/

 

[verulian]

Oh, thank you. Yes, I too am running on Hyper-V like that poster is noting. Unfortunately I'm not seeing a clear way to change this. I see they are running on Windows 10, but I'm running on Windows Server. Do you have a "Hyper-V Suggested Settings" page somewhere that gives details for each OS version and screenshots?

 

[verulian]

I found it! It took a little digging, but after going to the "Hyper-V Manager" right clicking on the virtual machine guest ("Proxmox"), click on "Settings", go to "Network Adapter", expand the "+" beside "Network Adapter", click on "Advanced Features", check "Enable MAC Address Spoofing", "Apply" or "OK" out of all of that and test again - AND IT WORKED!

Please consider adding a Proxmox Hyper-V Nesting FAQ or Tutorial. I think it would help a lot since so many people would like to run it on Windows laptops or servers for different reasons.

 

[oguz]

glad to be of help!

Please consider adding a Proxmox Hyper-V Nesting FAQ or Tutorial. I

we don't really want to recommend people to use nested virtualization as it can significantly lower the performance and increase overhead..

nothing hyper-v specific but you can find some information about nesting here[0]

[0]: https://pve.proxmox.com/wiki/Nested_Virtualization