IPMenu is a very able program, yet simple to operate and not too demanding on resources nor bandwidth. It is a console based program, so it works perfect over an SSH connection for example. It works perfectly on machines running over a simple and old modem as well.
As you can see from the screenshot, it is able to handle all iptables functionality, including filtering, mangling and nating. It is also able to handle routing tables and bandwidth shaping and to save and restore rulesets. You can add new rules directly into the currently running iptables script easily, and handle all of the different tables. Including adding and removing custom chains.
As you can see from the screenshot above, the program is rather basic, but still able to handle most situations rather well. And first of all, it is very simple, and can be used for remote administration simply enough, and since it runs on top of ssh via a standard console, it should also be fairly secure. You can find the homepage of IPMenu at http://users.pandora.be/stes/ipmenu.html.