The Advanced tab holds many miscellaneous advanced options. Here you can also set up your own simple protocols for opening a small hole through your firewall to support an ad hoc protocol. For example, accessing a remote administration web interface that is served from a non-standard port number.
When the Show advanced protocol help checkbox is ticked, extra information is given for the help text for protocols on the protocol tab. The extra information includes the kinds of network connections the protocols uses.
The Allow TCP timestamps checkbox lets you turn TCP timestamps on or off. Leaving TCP timestamps turned on makes it possible for outsiders to calculate how long your machine has been running since it was last booted. nmap -O can do this. Generally, unless you are connected to a high speed network connection chances are you have no good reason to have TCP timestamps turned on.
The Restore to factory defaults clears the firewall configuration and resets it back to how it was the first time Guarddog was run.
The two input widgets next to Local Dynamic Port Range allows you to specify the range of port numbers used by the operating system for the source port of new out going connection. When a connection is made to a port on an external machine, the source port of the connection is usually specified by the application. It is left up to the operating system to choose a suitable free source port number. The local dynamic port range is just range of port numbers that the operating system will look in whether finding an available source port.
Generally, there is little reason to change this. It might only become important on machines that need to have an unusually high number of connections active at the same time.
If you are using DHCP to configure an network interface, then you will need to specify the name of the interface in the Enable DHCP on interface: widget.
If you are running a DHCP server on an network interface, then you will need to specify the name of the interface in the Enable DHCP server on interface: widget.
Currently DHCP is limited to a single interface. This limitation will be removed in a future version of Guarddog
Import and Export allow you to save the current configuration to a file, and read it back into Guarddog again. When you click on either of these buttons, a file dialog appears where you can choose the file to import from, or export to.
The Description text box allows you enter any short notes about the current firewall configuration
In addition to all the protocols that Guarddog supports, it is also possible to specify your own custom protocols.
In the middle of the User Defined Protocols group is the list of current user defined protocols. Use the New Protocol button to create a new blank protocol. The Delete Protocol button naturally deletes the currently selected user defined protocol.
After creating a new protocol you can give it a name using the Name text box. The Type widget lets you specify what IP protocol your user defined protocol uses. You have the choice between TCP and UDP. In the Port widget you specify the TCP or UDP port on the server or remote machine that the protocol must connect to. For UDP protocols use the bidirectional checkbox to specify if the protocol is bidirectional and requires packets to travel in both directions. Once a user defined protocol has been specified here , it becomes available on the Protocol tab under the User Defined protocol category. There it can be turned on or off just like any other built-in protocol.