CCNA Foundations Day 6: Layer 3 Routing Troubleshooting

Archive lab

Troubleshoot classic static routing and connectivity issues in a 3-router, 2-site network. Faults seeded include a missing return route, wrong next-hop/mask, and a missing/misconfigured default route. Learners must identify and correct Layer 3 faults to restore end-to-end reachability between branch clients.

Learning objectives

• Diagnose typical static routing faults including missing return routes, wrong next-hop, and default route errors.
• Utilize 'show ip route', 'ping', and 'traceroute' to verify Layer 3 reachability.
• Restore bi-directional communication by correcting configuration errors.
• Understand common symptoms and remediation steps for one-way reachability.

Troubleshooting focus

• Identify a missing static route causing one-way communication.
• Detect and fix incorrect next-hop addresses and subnet masks in static routes.
• Spot missing or incorrect default routes limiting remote destination reachability.
• Verify fixes using Layer 3 diagnostic commands and end-to-end pings.