20-12-2012, 05:54 PM
Configuring EIGRP
1Configuring EIGRP.ppt (Size: 1,010 KB / Downloads: 34)
Objectives
Upon completing this lesson, you will be able to:
Describe EIGRP features and operation
Explain how EIGRP discovers, chooses, and maintains routes
Explain how EIGRP supports the use of VLSM
Explain how EIGRP operates in an NBMAenvironment
Explain how EIGRP supports the use of routesummarization
EIGRP Features
Advanced distance vector
100% loop free
Fast convergence
Easy configuration
Less network design constraints than OSPF
Advantages of EIGRP
Multicast instead of broadcast
Use of link bandwidth and delay
EIGRP metric = IGRP metric x 256(32 bit versus 24 bit)
Unequal cost path load balancing
More flexible than OSPF
Manual summarization can be done in any interface at any router within the network
EIGRP in IP Packets
EIGRP is an advanced distance vector routing protocol:
Automatically establishes neighbor relationships with peer devices
Relies on IP packets for delivery of routing information
EIGRP Neighbor Relationship
Two routers become neighbors when they see each other’s hello packet
Hello address = 224.0.0.10
Hellos sent once every 5 seconds on the following links:
Broadcast media: Ethernet, Token Ring, FDDI
Point-to-point serial links: PPP, HDLC, point-to-point Frame Relay/ATM subinterfaces
Multipoint circuits with bandwidth greater than T1: ISDN PRI, SMDS, Frame Relay
EIGRP Summarization—Manual
Manual summarization
Configurable on a per-interface basis in anyrouter within network
When summarization is configured on an interface, the router immediately creates a route pointing to Null0
Loop prevention mechanism
When the last specific route of the summary goes away, the summary is deleted
The minimum metric of the specific routes is used as the metric of the summary route
EIGRP Query Process
Queries are sent out when a route is lost and no feasible successor is available
The lost route is now in active state
Queries are sent out to all of its neighbors on all interfaces except the interface to the successor
If the neighbors do not have the lost route information, queries are sent out to their neighbors