EIGRP – Part 4 (Other EIGRP Properties)

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Key Configurations on EIGRP

EIGRP is an Enhanced Dynamic Routing Protocol that provide many methods for a good Routing Protocol implementation. In this lesson, we will focus on some of the key methods of EIGRP and we will learn these key methods with many EIGRP config examples. We will do some of the Key Configurations on EIGRP that will help you to do a better EIGRP implementation.

Here, we will learn the below methods of EIGRP:

  • EIGRP Route Summarization
  • Passive Interfaces
  • Unicast Neighbors
  • EIGRP Stub
  • EIGRP Authentication
  • Load-Balancing in EIGRP

Now, let’s focus on these key EIGRP methods, learn and configure each of them with different EIGRP Configuration Examples.


You can test your Routing Knowledge on CCNP Route Practice Tests Page!


EIGRP Route Summarization

 

By default EIGRP summarizes the classfull addresses. So generally “no auto-summary” command is used on Cisco router to avoid this situation. In the EIGRP Configuration below, you can find an example of  EIGRP Route Summarization.

Router (config) # router eigrp 100
Router (config-router) # no auto-summary

You can also use EIGRP Summary Routes manually. You can use this by “ip summary-address” command on Cisco Routers. Below there is a route summarization with 10.0.0.0/8 prefix.

Router (config) # interface fa0/1
Router (config-if) # ip summary-address eigrp 100  10.0.0.0 255.0.0.0

Passive Interface

If you want to prevent one interface or all interfaces to receive EIGRP update and EIGRP hello packets , you can use “passive interface” command. By using this command, no update and hello packets come to that interface anymore.

For example, with “passive interface” command, you can prevent fa0/1 to receive update and hello packets like below EIGRP Config.

Router (config) # router eigrp 100
Router (config-router) # passive-interface fa0/1

You can also prevent all the interfaces to receive these packets and then you can open the ones you want. Below, firstly we prevent all interfaces and then allow fa0/5 and fa0/6.

Router (config) # router eigrp 100
Router (config-router) # passive-interface default
Router (config-router) # no passive-interface fa0/5
Router (config-router) # no passive-interface fa0/6

Unicast Neighbours

In EIGRP, Multicast Address 224.0.0.10 is used . If you want , you can change this to a specific neighbour address with “neighbour ip-address” command on Cisco routers. You can use this command like below:

Router (config) # router eigrp 100
Router (config-router) # neighbour 10.0.0.1

EIGRP Stub

EIGRP Stub router is the router that is not a transit router and only has one EIGRP neighborship. EIGRP Stub provides less queries. You can configure EIGRP Stub, like below:

 Router (config) # router eigrp 100 Router (config-router) # eigrp stub [receive-only, connected , static, summary, redistributed] /pre>
After stub command, you can optionally use some parameters. These parameters are receive-only, connected , static, summary, redistributed. The meaining of these parameters are given below:
Receive-only : Update are not shared with neighbors.
Connected : Only connected routes will be advertised.
Static : Only static routes will be advertised.
Summary :  Only summary routes will be advertised.
 

EIGRP Authentication

EIGRP supports MD5 Authentication.For reliable transfer between two EIGRP Neighbor, MD5 Authentication is used. The authentication parameters between two neighbours must match. Below, you can find an example configuraiton for EIGRP Authentication Configuration on Cisco routers.
You can test your Routing Knowledge on CCNP Route Practice Tests Page!

EIGRP Article Series...
EIGRP - Part 1
EIGRP - Part 2 (EIGRP Tables)
EIGRP - Part 3 (EIGRP Packet Types and Neighborship)
EIGRP - Part 4 (Other EIGRP Properties)
EIGRP - EIGRP Configuration with Packet Tracer

EIGRP for IPv6 - EIGRP for IPv6 Overview
EIGRP for IPv6 - EIGRP for IPv6 Configuration on Cisco IOS

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