check firewall zones in pppoe test

tests/pppoe/configuration.nix

@@ -15,6 +15,7 @@ rec {
     ../../modules/ppp
     ../../modules/dnsmasq
     ../../modules/network
+    ../../modules/firewall
   ];
 
   services.pppoe = svc.pppoe.build {
@@ -23,6 +24,13 @@ rec {
     password = "NotReallyTheSecret";
   };
 
+  services.firewall = svc.firewall.build {
+    zones = {
+      wan = [ services.pppoe ];
+      lan = [ services.lan4 ];
+    };
+  };
+
   services.defaultroute4 = svc.network.route.build {
     via = "$(output ${services.pppoe} address)";
     target = "default";
@@ -39,5 +47,5 @@ rec {
     domain = "fake.liminix.org";
   };
 
-  defaultProfile.packages = [ pkgs.hello ];
+  defaultProfile.packages = with pkgs; [ nftables hello ];
 }