anchor.diff:              type = types.addCheck types.str (n: n == "tun" || n == "tap");
               description = ''
                 The type of virtual interface used for the network connection
  +            '';
  +          };
  +
  +          listenAddress = mkOption {
  +            default = null;
  +            type = types.nullOr types.str;
  +            description = ''
  +              The ip adress to bind to.
               '';
             };
   
  
positive.code:             '';
            };
  
            debugLevel = mkOption {
              default = 0;
              type = types.addCheck types.int (l: l >= 0 && l <= 5);
  
negative.code:             text = ''
                Name = ${if data.name == null then "$HOST" else data.name}
                DeviceType = ${data.interfaceType}
                ${optionalString (data.ed25519PrivateKeyFile != null) "Ed25519PrivateKeyFile = ${data.ed25519PrivateKeyFile}"}
                ${optionalString (data.listenAddress != null) "BindToAddress = ${data.listenAddress}"}
                Device = /dev/net/tun
                Interface = tinc.${network}
                ${data.extraConfig}
  