anchor.diff:    };
   
     nodes.server = { ... }: {
  -    networking.nameservers = [ "127.0.0.1" ];
  +    networking.nameservers = [ "::1" ];
   
       services.namecoind.rpc = {
  -      address = "127.0.0.1";
  +      address = "::1";
         user = "namecoin";
         password = "secret";
         port = 8332;
  
positive.code:           assert "example.com" in server.succeed("dig SOA @localhost -p 5333 bit")
  
        with subtest("bit. zone forwarding works"):
            assert "1.2.3.4" in server.succeed("host test.bit")
      '';
  })
  
negative.code:       script = ''
          while true; do
            echo -e "HTTP/1.1 200 OK\n\n $(<${fakeReply})\n" \
              | ${pkgs.netcat}/bin/nc -N -l ::1 8332
          done
        '';
      };
  