NET4009_Module 2 - Tshooting EIGRPv4v6

Troubleshooting EIGRP for IPv4/IPv6

General Troubleshooting Steps

• Verify EIGRP configuration on routers

• Check EIGRP neighbor relationships

• Ensure correct autonomous system (AS) numbers

• Confirm interface IP addresses and subnet masks

• Review EIGRP metrics and administrative distances

Common Issues

• Missing or incorrect network statements

• Mismatched EIGRP parameters (K values, timers)

• Interface issues (shutdown, incorrect encapsulation)

• ACLs blocking EIGRP packets

• MTU mismatches causing fragmentation

Commands to Use

• show ip eigrp neighbors / show ipv6 eigrp neighbors

• show ip eigrp topology / show ipv6 eigrp topology

• debug eigrp packets

• show ip protocols / show ipv6 protocols

• show ip route eigrp / show ipv6 route eigrp

Tools and Techniques

• Use ping and traceroute to test connectivity

• Check routing tables for EIGRP routes

• Use Wireshark for packet analysis

• Compare configurations across devices

• Utilize simulation tools for testing scenarios

Configuration Verification

• Validate EIGRP authentication settings

• Ensure route summarization is correctly configured

• Verify passive interfaces

• Check for route filtering (distribute-lists)

IPv4 vs. IPv6 Considerations

• Understand differences in EIGRP for IPv4 and EIGRP for IPv6

• Check for dual-stack configurations

• Ensure proper IPv6 addressing and link-local addresses

• Verify EIGRPv6 configuration commands and syntax

Documentation and Logging

• Maintain logs of changes made during troubleshooting

• Document EIGRP configurations for reference

• Use network diagrams to visualize EIGRP topology

Performance Monitoring

• Monitor CPU and memory usage on routers

• Assess EIGRP convergence times

• Check for route flapping or instability

Best Practices

• Regularly back up router configurations

• Keep EIGRP configurations consistent across devices

• Implement redundancy for critical EIGRP paths

• Educate staff on EIGRP troubleshooting techniques