Lab 60 - EIGRP Unicast Communication

Prerequisites: CCNP level skills.

Topology

Pic. 1 - Topology Diagram.

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

Note!
EIGRP uses 224.0.0.10 address to send most the packets. It can use unicast instead. In such situations, all neighbors must be configured to use unicast.

Task1
Configure R1 to use unicast instead of multicast while exchanging EIGRP packets.

Lab Solution

Task1

Configure R1 to use unicast instead of multicast while exchanging EIGRP packets.

R1 Configuration:

!

router eigrp 1
 network 10.1.13.1 0.0.0.0
 network 10.1.123.1 0.0.0.0
 network 10.1.124.1 0.0.0.0
 network 172.16.101.1 0.0.0.0
 no auto-summary
 neighbor 10.1.124.4 FastEthernet1/0
 neighbor 10.1.124.2 FastEthernet1/0

!

Notice!

At this moment both routers: R2 and R4, are no longer considered neighbors since they still use multicast for EIGRP packets.

Pic. 2 - R1's EIGRP Neighbors.

R2 Configuration:

!

router eigrp 1
 network 10.1.123.2 0.0.0.0
 network 10.1.124.2 0.0.0.0
 network 172.16.102.2 0.0.0.0
 no auto-summary
 neighbor 10.1.124.4 FastEthernet1/0
 neighbor 10.1.124.1 FastEthernet1/0

!

R4 Configuration:

!

router eigrp 1

 passive-interface Loopback0
 passive-interface Loopback1
 network 10.1.124.4 0.0.0.0
 network 172.16.104.4 0.0.0.0
 network 172.16.144.4 0.0.0.0
 no auto-summary

 neighbor 10.1.124.2 FastEthernet1/0
 neighbor 10.1.124.1 FastEthernet1/0

!

Note!
Loopbacks are configured in passive-interface mode so the 'debug ip packet detail' does not send EIGRP packets out these interfaces.

Verification:

Pic. 3 - R4's EIGRP Neighbors.

Debug ip packet detail proves that unicast is used while exchanging EIGRP packets.

Pic. 4 - Debug IP Packets Detail.