Module 3: EIGRP

Module 3: EIGRP


EIGRP is a Cisco-proprietary routing protocol that is based on IGRP.
EIGRP supports CIDR and VLSM which allows network designers to maximize address space. When compared to IGRP which is a classful routing protocol, EIGRP boasts faster convergence times, improved scalability, and superior management of routing loops.
Furthermore, EIGRP can replace Novell RIP and AppleTalk Routing Table Maintenance Protocol (RTMP). EIGRP serves both IPX and AppleTalk networks with powerful efficiency.
EIGRP is often described as a hybrid routing protocol that offers the best of distance vector and link-state algorithms.
EIGRP is an advanced routing protocol that relies on features commonly associated with link-state protocols. Some of the best features of OSPF, such as partial updates and neighbor discovery, are similarly put to use by EIGRP. However, EIGRP is easier to configure than OSPF.
EIGRP is an ideal choice for large, multi-protocol networks built primarily on Cisco routers.
This module covers common EIGRP configuration tasks. The emphasis is on ways in which EIGRP establishes relationships with adjacent routers, calculates primary and backup routes, and responds to failures in known routes to a particular destination.
A network is made up of many devices, protocols, and media that allow data communication to occur. When a network component does not work correctly, it can affect the entire network. In any case, network administrators must quickly identify and troubleshoot problems when they arise. The following are some reasons why network problems occur:

• Commands are entered incorrectly
• Access lists are constructed or placed incorrectly
• Routers, switches, or other network devices are misconfigured
• Physical connections are bad

A network administrator should troubleshoot in a methodical manner with the use a general problem-solving model. It is often useful to check for physical layer problems first and then move up the layers in an organized manner. Although this module focuses on how to troubleshoot Layer 3 protocols, it is important to troubleshoot and eliminate any problems that may exist at the lower layers.
This module covers some of the objectives for the CCNA 640-801 and ICND 640-811 exams.  
Students who complete this module should be able to perform the following tasks:

• Describe the differences between EIGRP and IGRP
• Describe the key concepts, technologies, and data structures of EIGRP
• Understand EIGRP convergence and the basic operation of the Diffusing Update Algorithm (DUAL)
• Perform basic EIGRP configuration
• Configure EIGRP route summarization
• Describe the processes used by EIGRP to build and maintain routing tables
• Verify EIGRP operations
• Describe the eight-step process for general troubleshooting
• Apply a logical process to troubleshoot routing
• Use the show and debug commands to troubleshoot RIP
• Use the show and debug commands to troubleshoot IGRP
• Use the show and debug commands to troubleshoot EIGRP

Use the show and debug commands to troubleshoot OSPF