EIGRP(Enhanced Interior Gateway Routing Protocol)


Enhanced Interior Gateway Routing Protocol

• Cisco proprietary protocol
• Classless routing protocol
• Includes all features of IGRP

• Metric (32 bit) : Composite Metric (BW + Delay + load + MTU + reliability )
• Administrative distance is 90 for Internal EIGRP

• Administrative distance is 170 for External EIGRP
• Updates are through Multicast ( )
• Max Hop count is 255 (100 by default)
• Supports IP, IPX and Apple Talk protocols
• Hello packets are sent every 5 seconds
• Convergence rate is fast

• Support VLSM and CIDR
It uses DUAL (diffusion update algorithm)
• Summarization can be done on every router
• Supports equal and unequal cost load balancing

 It maintains three tables

   1.Neighbor table
   2.Topology table
   3.Routing table 

But, It Works only on Cisco Routers

Configuring EIGRP
Router(config)# router eigrp <as no>
Router(config-router)# network <Network ID> 

ON Router1:

Router1 # config terminal

Router1(config) # ip routing

Router1(config) # router eigrp 100 ( Autonomous system NO is 100)

Router1(config-router) # network

Router1(config-router) # network

Router1(config-router) # exit

Router1(config) # exit 

Router1 # show ip route

ON Router2:

Router2 # config terminal

Router2(config) # ip routing

Router2(config) # router eigrp 100 ( Autonomous system NO is 100)

Router2(config-router) # network

Router2(config-router) # network

Router2(config-router) # exit

Router2(config) # exit

Router2 # show ip route



show ip route eigrp      Shows only EIGRP entries in the routing table

show ip eigrp neighbors Shows all EIGRP neighbors

show ip eigrp topology Shows entries in the EIGRP topology table

debug eigrp packet Shows Hello packets sent/received between adjacent routers

Debug ip eigrp notification Shows EIGRP changes and updates as they occur on your network

Read also:


OSPF(Open Shortest path first)

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