the_prg_server_configuration/nix-system-configs/modules/local/networking_local.nix

{
  config,
  pkgs,
  lib,
  ...
}: {
  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = {
  #   enable = true;
  #   enableSSHSupport = true;
  # };

  # List services that you want to enable:

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

  services.resolved.enable = false;

  # Use this clean static network configuration instead:
  networking.useDHCP = false;
  networking.networkmanager.enable = false; # Disable NetworkManager

  networking.interfaces.ens18 = {
    ipv4.addresses = [
      {
        address = config.local.address or "10.1.1.100";
        prefixLength = 24;
      }
    ];
  };

  networking.defaultGateway = {
    address = "10.1.1.1";
    interface = "ens18";
  };

  # Explicitly set DNS
  networking.nameservers = ["10.1.1.2"]; # PiHole DNS
}