EIGRP PART-1 (EIGRP Overview with Configuration)

ABOUT EIGRP PROTOCOL

EIGRP stands for Enhanced Interior Gateway Routing Protocol. It is also known as hybrid routing protocol because it has combination of both distance vector and link state routing protocol. EIGRP supports classless routing and VLSM, route summarization, incremental updates, load balancing and many other useful features. It is a CISCO proprietary protocol, so all routers in a network that is running EIGRP must be CISCO router. EIGRP uses the Diffusing-Update Algorithm (DUAL) to perform loop-free routing and calculate the shortest path. EIGRP routers use multicast address 224.0.0.10 to exchange route information. Administrative Distance (AD) value of EIGRP is 90.

POINTS TO BE REMEMBER

Full form:                            Enhanced Interior Gateway Routing Protocol

Nature:                                Hybrid (combination of distance vector and Link state)

Algorithm:                            DUAL (Diffusing-Update-Algorithm)

Multicast Address:                 224.0.0.10

AD value:                              90

Matrix:                                  bandwidth, delay, load, and reliability

Maximum hop count limit:     224 hops but default is 100

EIGRP CONFIGURATION

For router 1

Router1(config)# router eigrp  1

Router1(config-router)# network 10.0.0.0              (connected network)

Router1(config-router)# network 40.0.0.0              (connected network)

Router1(config-router)# end

Router1# write

For router 2

Router2(config)# router eigrp  1

Router2(config-router)# network 20.0.0.0              (connected network)

Router2(config-router)# network 40.0.0.0              (connected network)

Router2(config-router)# network 50.0.0.0              (connected network)

Router2(config-router)# end

Router2# write

For router 3

Router3(config)# router eigrp  1

Router3(config-router)# network 50.0.0.0              (connected network)

Router3(config-router)# network 30.0.0.0              (connected network)

Router3(config-router)# end

Router3# write

To show routing table

Router3# show ip route