FrazierWall Linux is a single floppy distribution Linux firewall that is based on the Linux Router Project. It is designed for use with ethernet base internet connections (such as cable modems or xDSL lines). It allows you to share such a connection with several other computers on a LAN. It is easy to setup and maintain, and is available in a Linux configurable software version.
The LARTC-HOWTO describes many advanced ways of routing and shaping traffic. Using the HOWTO, you will be able to shape traffic in myriad ways, which will help you lower latency for interactive use when others are downloading or uploading. It will also teach you how to limit certain hosts/protocols' bandwidth usage. It also explains many aspects of routing using the 'ip' tool from the iproute2 suite.
NetTraf consists of a daemon that gets information from a Linux interface and sends it on the network to NetTraf clients. Clients then can use the information to show to the user how the connection is performing. This program is mostly useful with dial-up connections on a masqueraded server, so all users on the network know when the connection is active, and if there is too much traffic on the line. This package DOES NOT comes with any client applications; you can find them on the homepage. The author needs help to develop a Linux client.
Xtradius is a radius server that permits you to handle user authentication and accounting request via external scripts. You can handle script requests for user accounting, user authentication, NAS start and NAS stop packets. You can also write additional information into the NAS detail logfile. Parameters to scripts are passed via command line options or environment variables, making it very simple to implement SQL-based user accounting, authentication and account expiration. It is also compatible with "standard" cistron radius server.
Dr.Morena is a tool to confirm the rule configuration of a firewall. It inspects all the firewall rules that are currently in effect, and tests these rules by sending various kinds of test packets through the firewall. This allows you to confirm that the rules that you intend to be in effect are actually in effect.
pingx is utility that uses the XNoOp(3x) call to see how fast your connection to your X server is. Wonder whether your X performance is slower in a SSH tunnel? pingx can give you hard numbers so you can find out. It has an option to print out some details about the X server as well. It's also useful to see if a destination X server is up so you can fire up x2x or similar applications intelligently.