Network bridge with static IP on host

Help
1

Solution

Ok I solved it. The problem was that gnome apparently autostarts network manager which interfered with my config. So what I did was to deactivate the network connection in the GUI and then use the following config:

  networking.useDHCP = false;
  networking.bridges = {
    "br0" = {
      interfaces = [ "enp8s0" ];
    };
  };
  networking.interfaces.br0.ipv4.addresses = [ {
    address = "10.10.10.10";
    prefixLength = 24;
  } ];
  networking.defaultGateway = "10.10.10.1";
  networking.nameservers = ["10.10.10.1" "8.8.8.8"];

With this everything works as expected. I can then set up a static IP in the VM and everything is working as specified.

Original message

My machine has one network interface enp8s0. Iā€™d like to have the following setup:

  1. Host with static IP 10.10.10.10/24, reachable on the internal network (e. g. over ssh and xRDP)
  2. KVM Virtual machine with static IP 10.10.10.11/24, reachable on the internal network
  3. Both machines need to be connected to the internet

Tested configurations

Bridged DHCP

  networking.useDHCP = false;
  networking.interfaces.enp8s0.useDHCP = true;
  networking.interfaces.br0.useDHCP = true;
  networking.bridges = {
    "br0" = {
      interfaces = [ "enp8s0" ];
    };
  };

This is the closest I got: when using this configuration the VM is completely reachable in the internal network and both machines have an internet connection. However: now the host is not reachable. Also: this is obviously missing the static IP config.

Bridged with static IP

  networking.useDHCP = false;
  networking.interfaces.enp8s0.useDHCP = true;
  networking.interfaces.br0.useDHCP = false;
  networking.bridges = {
    "br0" = {
      interfaces = [ "enp8s0" ];
    };
  };
 networking.interfaces.br0.ipv4.addresses = [ {
   address = "10.10.10.11";
   prefixLength = 24;
 } ];
 networking.defaultGateway = "10.10.10.1";
 networking.nameservers = ["10.10.10.1" "8.8.8.8"];

With this config I neither have internet nor LAN access in the VM. On the host I have internet but no access to the LAN.

I tested 3 more combinations of the above but those were just desperate experiments.

Can someone enlighten me?

2 Likes