netfilter Operation: Part Nine (Lokkit)


Lokkit in action under Ubuntu.

Using Lokkit

Lokkit is an ncurses-based menu for configuring your netfilter firewall that is part of the GNOME desktop. Lokkit is available for most major distributions and can be installed by default on some (such as Fedora). It asks a small number of simple questions and writes a firewall rule set for you. To start Lokkit, type lokkit in a terminal window. [If you don’t have lokkit, you can install it from the repos using the apt-get command: sudo apt-get install lokkit]. If you want to review the firewall settings without running the firewall, type:

sudo lokkit -n

To see what services/ports can be managed/opened using lokkit, type:

sudo lokkit –list-services

You can navigate the menus using the Tab key and the space bar to toggle the equivalent of radio buttons, such as the Enable and Disabled options shown here. If you select Enabled on this screen, the default ruleset is applied. To edit any custom settings, press Tab until the Customize button is highlighted and then press Enter.

Lokkit does provide a little more flexibility than the Security Level configuration GUI discussed previously; however, it is still limited. By selecting an interface in Trusted Devices, all traffic from that interface will be permitted. This would typically be used to select the inside interface and designate it as trusted. You do have the option of enabling MASQUERADE. The interface you select is the one that will NAT outbound traffic; therefore, you would generally select your external interface. Some pre-defined services are available, and you can enter your own service information in the “Other ports” section. Once you are satisfied with your choices, press OK and then Enter. This will take you back to the main screen, where you press OK and then Enter to apply the changes.

If you attempt to configure an interface for MASQUERADE, it must also be marked as trusted or Lokkit will generate an error, Bear in mind that although MASQUERADE is limited, it has enough flexibility to configure a firewall similar to a typical home firewall/router device. This makes Lokkit a handy little utility to have in your repertoire should you need to configure a simple firewall quickly. The value of this utility is also increased, because it is available for a wide number of Linux distributions.

External Links:

Lock it down quickly with Lokkit at

Linux Firewall – The Second Line of Defense at Linuxtopia

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