I am a huge fan of packet analysis to ensure your network devices are configured and behaving as you expect them to be.
In this video, I analyze multicast and broadcast packets, focusing on two Cisco routing protocols -- HSRP and EIGRP -- as well as Spanning Tree Protocol (STP) and Cisco Discovery Protocol (CDP). Specifically, I go over some of the protocol contents, what they mean and what you might want to tune.
As you go through packets, it's important to ask yourself the following questions:
- Does this protocol need to be on this segment?
- Is this protocol properly configured?
- Is there any further tuning that could be applied to this protocol?
- Are there any security considerations for network protocols (i.e., clear text information)?