EIGRP-Enhanced Interior Gateway Routing Protocol

It is Described as Hybrid Routing Protocol
Administrative Distance(AD)-90
Supports CIDR and VLSM
It uses Diffusion Algorithm to find Best Path
It uses RTP(Reliable Transport Protocol)
Multiple Protocol Support
Fast Convergence

Now we are going to see EIGRP Routing configurations with simple network topology using packet tracer,

Step 1:First Create a topology like this,and configure ip address to

all interfaces and PC.

Router R1,Configuration

In Global configuration mode,

R1(config)#interface fastethernet 0/0
R1(config-if)#ip address
R1(config-if)#no shutdown

Once you have given no shutdown command the port become up

R1(config)#interface serial 2/0
R1(config-if)#ip address
R1(config-if)#clock rate 64000
R1(config-if)#encapsulation ppp
R1(config-if)#no shutdown

i.e.Always keep in mind to configure clock rate at DCE(Data Communication Equipment).we can see clock symbol at the serial interface that is DCE other End is DTE(Data Terminal Equipment).To
avoid confusion just give this command on both side.

Now, "Interface Serial2/0, changed state to down" ,Because other end of the serial interface not configured.So we have to configure other end of the serial interface in R2,then this interface become up.

Router R2,Config

In Global configuration mode,

R2#config terminal
R2(config)#interface serial 2/0
R2(config-if)#ip address
R2(config-if)#encapsulation ppp
R2(config-if)#no shutdown

Interface Serial2/0 and Line protocol on Interface Serial2/0 changed state to up

R2(config)#interface serial 3/0
R2(config-if)#ip address
R2(config-if)#clock rate 64000
R2(config-if)#encapsulation ppp
R2(config-if)#no shutdown

Router R3,Config

In Global configuration mode,

R3(config)#interface serial 3/0
R3(config-if)#ip address
R3(config-if)#encapsulation ppp
R3(config-if)#no shutdown

Interface Serial3/0 and Line protocol, changed state to up

R3(config)#interface fastethernet0/0
R3(config-if)#ip address
R3(config-if)#no shutdown

Interface fastethernet0/0 and line protocol,changed state to up

After all ip address assigned then lights in all interfaces  become green.If anything wrong we get red or amber.

Step 2:Now we see how to configure EIGRP routing protocols in this routers.

R1 Router,In Global Configuration mode,

R1(config)#router eigrp 200

R2 Router,In Global Configuration mode,

R2(config)#router eigrp 200

R3 Router,In Global Configuration mode,

R3(config)#router eigrp 200

i.e.here 200 is Atonomous System Number,it is used to grouping of routers under common admistration,Routers in different Atonomous Number
will not communicate with each other.So,Atonomous should be same in all routers.

Step 3:Now check the routing table by giving this command,

In Router R1,Privileged mode

R1#show ip route

Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route

Gateway of last resort is not set

C is directly connected, FastEthernet0/0
C is directly connected, Serial2/0
D [90/21024000] via, 00:04:42, Serial2/0
D [90/21026560] via, 00:02:34, Serial2/0

Router R1 having all networks information in its routing table,Check for R2 and R3 also.

Step 4:Now click on Pc and select Desktop->command prompt,then check connectivity between and


Pinging with 32 bytes of data:

Request timed out.
Reply from bytes=32 time=15ms TTL=125
Reply from bytes=32 time=13ms TTL=125
Reply from bytes=32 time=16ms TTL=125

Ping statistics for
    Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
    Minimum = 13ms, Maximum = 16ms, Average = 14ms

Verifying EIGRP Configurations

In Privileged Mode,

show ip route
show ip protocol
show ip eigrp topology

Post a Comment

  1. Its really a nice explanation ,but iam little bit confused ,that without IP ROUTE how its possible to make ping, and If its because of point-to -point protocol ,(is it is a alternate of ip route .)
    I never use PPP thats why totally confuseeee ,please help me out

    1. ip route command only for static routing.. this is dynamic routing...see step 3 its for dynamic