Chapter 7. Employing Enhanced IGRP

Terms you'll need to understand:

• Diffusing update algorithm (DUAL)

• Smooth round trip time (SRTT)

• Retransmission timeout (RTO)

• Successor

• Feasible distance (FD)

• Feasible successor (FS)

• Stuck in active (SIA)

• Holdtime

• Uptime

• Reliability

Techniques you'll need to master:

• Learning how EIGRP discovers, chooses, and manages routes

• Configuring EIGRP for VLSM and route summarization

• Deploying EIGRP in several NBMA environments

• Configuring and verifying EIGRP operations

Cisco improved its proprietary Interior Gateway Routing Protocol with EIGRP by delivering a hybrid protocol that uses elements of distance-vector and link-state characteristics. EIGRP stands for Enhanced Interior Gateway Routing Protocol. Although EIGRP can be used to route IP, IPX, and AppleTalk packets, this book focuses exclusively on IP routing with EIGRP as covered on the Cisco BSCI exam. EIGRP functions like a distance-vector protocol to find the optimal path on a network and utilize link-state properties when discovering neighbors and managing changes in the topology.