Chapter 8. Aggregating Switch Links

This chapter covers the following topics that you need to master for the CCNP BCMSN exam:

• Switch Port Aggregation with EtherChannel This section discusses the concept of aggregating, or "bundling," physical ports into a single logical link. Methods for load-balancing traffic across the physical links also are covered.

• EtherChannel Negotiation Protocols This section discusses two protocols that dynamically negotiate and control EtherChannels: Port Aggregation Protocol (PAgP), a Cisco proprietary protocol, and Link Aggregation Control Protocol (LACP), a standards-based protocol.

• EtherChannel Configuration This section discusses the Catalyst switch commands needed to configure EtherChannel.

• Troubleshooting an EtherChannel This section gives a brief summary of things to consider and commands to use when an aggregated link is not operating properly.

In previous chapters, you learned about campus network design and connecting and organizing switches into blocks and common workgroups. Using these principles, end users can be given effective access to resources both on and off the campus network. However, today's mission-critical applications and services demand networks that provide high availability and reliability.

This chapter presents technologies that you can use in a campus network to provide higher bandwidth and reliability between switches.