Static Routing and Distance Vector Routing Protocols - CCIE Routing and Switching Exam Certification Guide - page 349

or metric changes. Update packets are acknowledged to ensure reliable transmission. Query
packets are sent to find feasible successors to a destination. Query packets are always multicast.

Reply packets are sent to respond to query packets. Reply packets provide a feasible successor
to the sender of the query. Reply packets are unicast to the sender of the query packet.

EIGRP Configuration
The configuration commands for EIGRP are similar to IGRP. After configuring the interfaces,
the router eigrp command enables the routing protocol. The networks are defined with the
network command.

Using the physical network described in Figure 7-6, the configurations for Router8, Router9,
and Router10 are presented in this section.

EIGRP Configuration Example Figure 7-6

Router9

Router10

172.16.4.0/30

.1

.1

.2

.1

172.16.2.0/24

172.16.1.0/24

.2

.1

Router8

172.16.3.0/28

Example 7-26 shows the configuration of Router8. EIGRP is configured with the autonomous
system number 100. EIGRP hellos are sent on all interfaces configured with an IP address
within 172.16.0.0. You use the variable subnet masks; the subnet mask on Ethernet 0 is /24
and on Token Ring 0 is /28.
Example 7-26 Configuration of Router8

hostname Router8
!
interface Ethernet0
ip address 172.16.1.2 255.255.255.0
!
interface TokenRing0
ip address 172.16.3.1 255.255.255.240
ring-speed 16
!
router eigrp 100
network 172.16.0.0

255.255.255.0

255.255.255.240