diff --git a/test-server/configuration.nix b/test-server/configuration.nix
index 7ffbd80..f70930b 100644
--- a/test-server/configuration.nix
+++ b/test-server/configuration.nix
@@ -22,8 +22,6 @@ in{
 
   # Enable networking
   #networking.networkmanager.enable = true;
-  networking.firewall.allowedTCPPorts = [ 22 53 80 443 ];
-  networking.firewall.allowedUDPPorts = [ 53 ];
 
   # Set your time zone.
   time.timeZone = "Europe/Vienna";
@@ -93,6 +91,7 @@ in{
 
   environment.systemPackages = with pkgs; [
     kate
+    nixos-option
     wget
     vim
     tcpdump
diff --git a/test-server/modules/ip-server.nix b/test-server/modules/ip-server.nix
index 76a33c0..56b9a37 100644
--- a/test-server/modules/ip-server.nix
+++ b/test-server/modules/ip-server.nix
@@ -2,7 +2,11 @@
   networking = {
     defaultGateway = "192.168.0.1";
     useDHCP = false;
-    firewall.enable = true;
+    firewall = {
+      enable = true;
+      allowedTCPPorts = [ 22 53 80 443 ];
+      allowedUDPPorts = [ 53 ];
+    };
     nameservers = [
       "127.0.0.1"
       "1.1.1.1"