Lab 40 - EIGRP Manual Summarization

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

Given the topology (pic. 1) enable EIGRP (AS 1) protocol on all interfaces. You should use one network statement on each router.

Task 2
On R3 check the routing table.

Task 3
Configure route summarization on R2 so that both loopback 1 and loopback 2 addresses are represented by a single EIGRP entry in the routing table. The summary route should not overlap any address space.

Task 4
Repeat the task 3 on R1. Check routing table on R3. It should see the two summary routes.

Lab Solution

Task 1

Given the topology (pic. 1) enable EIGRP (AS 1) protocol on all interfaces. You should use one network statement on each router.

R1, R2, R3 Configuration:

!

router eigrp 1
 network 0.0.0.0
 no auto-summary

!

Notice!
Automatic summarization has been disabled ('no auto-summary') as per task 3 and task 4 requirement.



Task 2

On R3 check routing table.

Pic. 2 - EIGRP Routing Table on R3.

Task 3

Configure route summarization on R2 so that both loopback 1 and loopback 2 addresses are represented by a single EIGRP entry in the routing table. The summary route should not overlap any address space.

R2 Configuration:

!

interface FastEthernet1/0
 ip address 10.1.12.2 255.255.255.0
 ip summary-address eigrp 1 192.168.2.0 255.255.254.0 5

!

Notice!

The summary command automatically adds (can be changed manually) Administrative Distance 5. Any route with AD between 1-4 can override it.

Pic. 3 - R2's Routing Table.

Notice!

The 'discard route' has been automatically added to R2's routing table (null0).

Pic. 4 - The Discard Route Administrative Distance: 5.

Pic. 5 - R3's Routing Table.

Task 4

Repeat the task 3 on R1. Check routing table on R3. It should see the two summary routes.

R1 Configuration:

!

interface Serial0/1
 ip address 10.1.13.1 255.255.255.0
 ip summary-address eigrp 1 192.168.0.0 255.255.254.0 5

!

Pic. 6 - R3's Routing Table.