nix/nixos/common/modules/networking.nix

{pkgs, config, ...}:  {
  # Enable networking with NetworkManager

  networking = {
    networkmanager = { 
      enable = true;
    };

    enableIPv6 = false;
    firewall = { 
      enable = true;
      allowedTCPPorts = [  ];
      allowedUDPPorts = [  ];
    };
  };
}