As with many debugging situations, digging into and resolving a network-based problem can seem like a lot of pure guess and magic. In the networking realm, not only do we have the host system’s processes and configurations to contend with, but also the exciting and often frustrating asynchronicity of network traffic. Some of the problems that can trigger a debug session are reports of lost packets, corrupt data, poor performance, even random system crashes. Not always do these end up as actual network problems, but as soon as the customer mentions anything about their wiring rack or routers, the network engineer is brought in and put on the spot. This post is intended not as a full how-to in debugging any particular network issue, but more a set of some of the tips and tools that we use when investigating network misbehavior