nixos/server/sshd.nix

{ ... }:
{
  services.openssh = {
    enable = true;
    ports = [ 2222 ];
    settings = {
      UseDns = true;
      PermitRootLogin = "no";
      PasswordAuthentication = false;
      GatewayPorts = "yes";
      LogLevel = "VERBOSE";
    };
  };
}