nixos-config/modules/system/network.nix

{
  config,
  ...
}:
{
  networking = {
    hostName = "${config.host.name}"; # Define your hostname

    # Pick only one of the below networking options.
    # wireless.enable = true; # Enables wireless support via wpa_supplicant.
    networkmanager.enable = true; # Easiest to use and most distros use this by default.

    # Configure network proxy if necessary
    # proxy.default = "http://user:password@proxy:port/";
    # proxy.noProxy = "127.0.0.1,localhost,internal.domain";

    # Open ports in the firewall.
    # firewall.allowedTCPPorts = [ ... ];
    # firewall.allowedUDPPorts = [ ... ];
    # Or disable the firewall altogether.
    # firewall.enable = false;
  };
}