The complexity of a network of workstations and modern networked applications can make performance tuning difficult. A telling comment from one networker was "You know you're on a network when some system you've never heard of comes up on your console and hangs your machine!". This paper aims to provide techniques for troubleshooting and tuning your network, and is organised into the following sections: 1. Background 2. Configuring a networked system 3. Tuning a networked system 4. Summary: Buy more RAM! Modern GUI applications need lots of RAM to work well; When looking for resource-hogging clients, start at the server and follow the trail; Tuning your kernel parameters is easy, and is essential for most systems; If your ethernet is overloading (more than 2-3% collisions, 20% load) then you need to partition it; Once your network has enough RAM and network bandwidth, it will need more CPU power.