Chapter 11: Packet Capture and Analysis in Linux
In this chapter, we'll be discussing packet capturing using Linux. In many respects, packets are the closest thing to the truth in the data center; the proverb that's frequently quoted is Packets Don't Lie. No matter what policies or convoluted configuration exists on hosts or firewalls, the host and application packets will always reflect what's happening. This makes packet capture and, more importantly, the analysis of those packets a key problem-solving and troubleshooting skill in the toolbox of a network administrator.
In particular, we'll cover the following topics:
- Introduction to packet capturing – the right places to look
- Performance considerations when capturing
- Capturing tools
- Filtering captured traffic
- Troubleshooting an application – capturing a VoIP telephone call
Let's get started!