EIGRP configuration step-by-step

Step-by-Step EIGRP Configuration (IPv4) 

1. Enter Configuration Mode
   Access the global configuration mode on the router.

Router> enable
Router# configure terminal

1. Enable EIGRP Process
   Start EIGRP using an Autonomous System (AS) number (1-65535). All routers in the same network must use the same AS number.Router(config)# router eigrp <AS-number>
2. Define Networks
   Advertise the directly connected networks. Use the network command followed by the network address. Optionally, use a wildcard mask for specific interfaces.Router(config-router)# network <network-address> [wildcard-mask] Example: network 192.168.1.0 or network 10.0.0.0 0.0.0.255
3. Disable Auto-Summary
   By default, older IOS versions may automatically summarize networks. Disable this to ensure accurate routing of subnets.Router(config-router)# no auto-summary
4. Configure Passive Interfaces (Optional)
   To prevent sending routing updates to devices that don’t need them (like LAN interfaces), configure interfaces as passive.Router(config-router)# passive-interface <interface-id>
5. Verify Configuration
   Check for EIGRP neighbors, protocols, and routing tables.Router# show ip eigrp neighbors Router# show ip route Router# show ip protocols  

Example Configuration

Router1(config)# router eigrp 100
Router1(config-router)# network 10.0.0.0
Router1(config-router)# network 192.168.1.0
Router1(config-router)# no auto-summary
Router1(config-router)# exit

Key Considerations

• Wildcard Mask: While optional, it is best practice to use wildcard masks to specify which interfaces run EIGRP.
• Neighbor Adjacency: If neighbors don’t form, check that the AS number is identical and that network statements cover the interfaces.
• Named Configuration: For more complex, flexible configurations, Cisco suggests EIGRP named mode, which supports IPv4 and IPv6 under one process.