Analyzing the Forwarding Path

Troubleshooting revolves around three big ideas: predicting what should happen, determining what is happening that is different than what should happen, and figuring out why that different behavior is happening. This next section discusses how to look at what is actually happening in a VLAN based on those MAC address tables, first using a summary of switch forwarding logic and then showing an example.

The following list summarizes switch forwarding logic including the LAN switching features discussed in this book:

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Step 1. Process functions on the incoming interface, if the interface is currently in an up/up (connected) ...

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