Lab 44 - Selective Summarization with a Leak Map

Prerequisites: CCNP level skills.

EIGRP (as per CCNP track) offers a plethora of ways to summarize the prefixes:

1. Automatic Summarization.
2. Summarization ('ip summary-address).
3. Summarization with a Default Route.
4. Summarization with a Floating Default Route (floating summary route).
5. Summarization with Administrative Distance 255.
6. Selective Summarization with a Leak Map.

Topology

Pic. 1 - EIGRP NBMA Topology.

Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1

EIGRP is running on all interfaces of all routers shown in the topology (pic. 1). On R1 summarize all EIGRP prefixes so that R3 receives only a default route.

Task 2
Configure R1 so that R3 receives a default route as well as 192.168.1.0/24 and 192.168.3.0/24.

Lab Solution

Task 1

EIGRP is running on all interfaces of all routers shown in the topology (pic. 1). On R1 summarize all EIGRP prefixes so that R3 receives only a default route.

Pic. 2 - R3's Routing Table Before Summarization.

R1 Configuration:

!

interface Serial0/1
 ip address 10.1.13.1 255.255.255.0
 ip summary-address eigrp 1 0.0.0.0 0.0.0.0 5

!

Verification:

Pic. 3 - R3' Routing Table After Summarization.

Task 2

Configure R1 so that R3 receives a default route as well as 192.168.1.0/24 and 192.168.3.0/24.

R1 Configuration:

!

access-list 1 permit 192.168.1.0 0.0.0.255
access-list 1 permit 192.168.3.0 0.0.0.255
!

route-map ADVERTISE permit 10
 match ip address 1
!
interface Serial0/1
 ip address 10.1.13.1 255.255.255.0
 ip summary-address eigrp 1 0.0.0.0 0.0.0.0 5 leak-map ADVERTISE

!

Verification:

Pic. 4 - R3's Routing Table.