Lab 16 Turn Off auto-summary for EIGRP

Objective

• To understand the auto-summary for EIGRP.
• auto summary at the class boundary.
• Disable auto summary in a network with discontinuous IP.

Topology

Basic Setting

IPs for computers and routers have been set up.

Requirements

Configure EIGRP on routers, and disable auto summary for discontinuous IPs.

On Router5, 2, 0 and 1

Router(config)#route eigr 10
Router(config-router)#network 172.16.0.0

On Router4 and 3

Router(config)#route eigr 10
Router(config-router)#network 172.16.0.0
Router(config-router)#network 10.0.0.0

On Router6

Router(config)#route eigr 10
Router(config-router)#network 10.0.0.0
Check summary

On Router6

Router#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 2 subnets
C 10.0.0.0 is directly connected, Serial3/0
C 10.0.1.0 is directly connected, Serial2/0
D 172.16.0.0/16 [90/20514560] via 10.0.0.1, 00:14:03, Serial3/0
[90/20514560] via 10.0.1.2, 00:13:41, Serial2/0
Router#
For 172.16.0.0/16 there are two routes, which is caused by incorrect summary.
Ping PC0 from Router6
Router#ping 172.16.10.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.10.2, timeout is 2 seconds:
..!.!
Success rate is 40 percent (2/5), round-trip min/avg/max = 13/14/15 ms
Router#ping 172.16.10.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.10.2, timeout is 2 seconds:
.!.!.
Success rate is 40 percent (2/5), round-trip min/avg/max = 14/16/19 ms
There is package discarding, which is cause yb incorrect summary.

Turn off auto summary for EIGRP

Run these commands on all routers
Router(config)#router e 10
Router(config-router)#no auto-summary
Router(config-router)#

On Router6

Router#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
D 10.0.0.0/8 [90/21024000] via 10.0.0.1, 00:01:20, Serial3/0
[90/21024000] via 10.0.1.2, 00:01:03, Serial2/0
C 10.0.0.0/24 is directly connected, Serial3/0
C 10.0.1.0/24 is directly connected, Serial2/0
172.16.0.0/16 is variably subnetted, 11 subnets, 2 masks
D 172.16.0.0/16 is a summary, 00:01:37, Null0
D 172.16.0.0/24 [90/22050560] via 10.0.1.2, 00:00:07, Serial2/0
D 172.16.1.0/24 [90/22048000] via 10.0.1.2, 00:00:28, Serial2/0
D 172.16.2.0/24 [90/21538560] via 10.0.1.2, 00:00:28, Serial2/0
D 172.16.3.0/24 [90/21536000] via 10.0.1.2, 00:00:45, Serial2/0
D 172.16.4.0/24 [90/21026560] via 10.0.1.2, 00:00:45, Serial2/0
D 172.16.5.0/24 [90/21024000] via 10.0.1.2, 00:01:03, Serial2/0
D 172.16.6.0/24 [90/20514560] via 10.0.1.2, 00:01:03, Serial2/0
D 172.16.8.0/24 [90/20514560] via 10.0.0.1, 00:01:20, Serial3/0
D 172.16.9.0/24 [90/21024000] via 10.0.0.1, 00:01:20, Serial3/0
D 172.16.10.0/24 [90/21026560] via 10.0.0.1, 00:01:20, Serial3/0
Router#ping 172.16.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.0.2, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 17/23/27 ms
Router#ping 172.16.10.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.10.2, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 14/16/20 ms
Router#
Note: after disable auto-summary, no summary at class boundaries will be made, and Router 6 can learn routing information for all network segments.