EIGRP operates as an advanced distance vector routing protocol that offers the best features of Cisco’s distance vector and link-state algorithms in TCP/IP and Open Systems Interconnection (OSI) networks.
Cisco developed IGRP (Internal Gateway Routing Protocol) using distance vector-type routing technology. The purpose of this protocol is that each router knows only the address (next-hop address) and distance (metric) on each remote network.
Each router announces routes with the corresponding metric, and each router listening to the routes sets the metric and propagates it to neighboring routers.
EIGRP is an improved version of IGRP and uses distance vector technology in addition. The convergence characteristics and operating efficiency of this protocol have been significantly improved.
Convergence technology in a network is based on research conducted at SRI International. DUAL is the algorithm used to obtain a loopless path to each point in the network.
This allows all routers involved in a topology to be synchronized at the same time. Routers that are not affected by topology changes are not included in the recalculation.
To better understand the working logic of EIGRP routing, you can install it Cisco Routers with Cisco simulator software and examine how the neighborhood is established.
Using the Packet Tracer software, you can enable this protocol on a Cisco Router and enable LANs in two or more segments to communicate.
How to Enable EIGRP on Cisco Router
To enable EIGRP on routers with Packet Tracer:
Step 1: If you have not previously installed the Cisco network simulator on your computer, refer to the following articles to install on Windows, Linux, macOS.
Step 2: After installation, drag and drop two Cisco Routers, Cisco Switch and Computer to the PT workspace.
Step 3: Click on the Routers to add a serial interface and add the HWIC-2T module to the device in the left pane of the pop-up window, and then connect the Routers with the Serial DCE cable.
Step 4: Cabling all devices in the network topology, and then define an IP block between the two Routers for the routing protocol. Also, define the IP block for the networks under the GigabitEthernet interfaces of the routers.
Step 5: Configure the IP block as a different address for the network between Cisco routers, and connect the PCs to the Switches and configure the TCP/IP settings.
Step 6: To open the Serial and GigabitEthernet interfaces of the routers, run the no shutdown command on the CLI and assign IP addresses to the interfaces according to the blocks you specify.
Step 7: After preparing all the devices in the topology, run the following commands on R1 and R2 to activate EIGRP Routing.
R1# conf t
R1(config)# router eigrp 1
R1(config-router)# network 10.1.1.0 0.0.0.3
R1(config-router)# network 192.168.5.0 0.0.0.255
R2# conf t
R2(config)# router eigrp 1
R2(config-router)# network 10.1.1.0 0.0.0.3
R2(config-router)# network 192.168.10.0 0.0.0.255
Step 8: After configuring EIGRP, you can verify the configuration by running the following show commands on the Routers!
show ip eigrp neighbors
show ip eigrp neighbors detail
show ip eigrp interfaces
show ip eigrp interfaces serial 0/0/0
show ip eigrp interfaces 100
show ip eigrp topology
show ip eigrp traffic
show ip route
show ip route eigrp
show ip protocols
1. RIP Protocol
2. Virtual LAN
3. OSPF Protocol
4. OSPF Configuration