eve-psr-nix0/nix/system/network.nix

{ ... }: {
  networking = {
    hostName = "eve-psr-nix0";
    firewall = {
      allowedTCPPorts = [ 22 80 443 7860 ];
      allowedUDPPorts = [ 22 80 443 53 1194 ];
      trustedInterfaces = [ "tun0" ];
    };
    nat = {
      enable = true;
      externalInterface = "enp1s0";
      internalInterfaces = [ "tun0" ];
    };
  };
}