{
  inputs',
  pkgs,
  lib,
  ...
}: let
  inherit
    (lib)
    concatMap
    getExe'
    ;
in {
  imports = [
    inputs'.self.nixosModules.ifstate
    inputs'.self.nixosModules.netnsIf
    ./pppoe-server.nix
    ./qemu-vm.nix
  ];
  nixpkgs.overlays = [
    inputs'.self.overlays.ifstate
    (final: _: {
      rp-pppoe = final.callPackage ./rp-pppoe.nix {
        ppp = final.ppp.overrideAttrs (_: {
          patches = [
            ./0003-Wait-for-ip-up-down-scripts.patch
            ./0002-Call-scripts-with-the-same-environ-as-pppd.patch
          ];
        });
      };
    })
  ];

  environment.systemPackages = [
    pkgs.tcpdump
  ];

  services.ifstate = {
    enable = true;

    settings = {
      interfaces = [
        {
          name = "wan";
          link = {
            kind = "physical";
            permaddr = "00:11:22:33:42:00";
            state = "up";
          };
        }
        {
          name = "internet";
          link = {
            kind = "vlan";
            link = "wan";
            vlan_id = 6;
            state = "up";
          };
        }
        {
          name = "www-br";
          link = {
            kind = "bridge";
            state = "up";
          };
        }
      ];
    };
  };

  services.pppoe-server.kpn = {
    interface = "internet";
    localAddress = "10.0.0.1";
    remoteAddressFile = pkgs.writeText "kpn-remote-address-file" ''
      10.67.15.1
    '';
    # ifUpScript = pkgs.writeShellScript "ppd-if-up" ''
    #   ${getExe' pkgs.iproute2 "ip"} link set dev "$PPP_IFACE" master ppp-br
    # '';
  };

  networking = {
    hostName = "jormungandr";
    useDHCP = false;
    firewall.enable = false;
  };

  virtualisation.qemu.options = [
    "-net nic,model=e1000,macaddr=00:11:22:33:42:00,netdev=wan"
    "-netdev stream,id=wan,addr.type=unix,addr.path=../../../midgard/link"
    # "-netdev vde,id=wan,sock=../../../midgard/switch"
  ];
}