EIGRP's Manual Summary Experience

topology diagram : R1 (e0/0)----(E0/1) R2 (e0/0)----(E0/1) R3

r1#sh IP int b

Interface ip-address OK? Methodstatus Protocol

ethernet0/0 12.1.1.1 YES Manual up

Loopback0 192.168.0.1 YES Manual up

Loopback1 192.168.1.1 YES Manual up

Loopback2 192.168.2.1 YES Manual up

Loopback3 192.168.3.1 YES Manual up

All-web-run eigrp

Scenario One :

if the r1eigrp is declared , net192.168.0.0 0.0.255.255

so look at the routing table on R3.

R3#sh IP Rout EIGRP

D 192.168.0.0/24[90/435200] via 23.1.1.2, 00:01:57, ETHERNET0/1

12.0.0.0/24 issubnetted, 1 subnets

D 12.1.1.0[90/307200] via 23.1.1.2, 00:02:45, ETHERNET0/1

D 192.168.1.0/24[90/435200] via 23.1.1.2, 00:01:57, ETHERNET0/1

D 192.168.2.0/24[90/435200] via 23.1.1.2, 00:01:57, ETHERNET0/1

D 192.168.3.0/24[90/435200] via 23.1.1.2, 00:01:57, ETHERNET0/1

network is r1 direct route in

Scenario Two : in case 1 under the conditions of On R1 ( or R2 ) Add : Eigrp Rollup Routes

R1 (config-if) #ip summary-address EIGRP 90 192.168.0.0255.255.252.0

R3#sh IP Rout EIGRP

12.0.0.0/24 issubnetted, 1 subnets

D 12.1.1.0[90/307200] via 23.1.1.2, 00:08:54, ETHERNET0/1

D 192.168.0.0/22[90/435200] via 23.1.1.2, 00:00:18, ETHERNET0/1

Description Manual rollup suppresses clear routing , produced a 192.168.0.0/22 . the routing

also produces D 192.168.0.0/22is A summary, 00:02:49, Null0 Prevent routing loops

then it means that the R1 knock network 192.168.0.0/16 is not in effect

This article from the "Erick" blog, declined to reprint!

EIGRP's Manual Summary Experience