CCNA Foundations: L3 & IP Routing Day 3

Archive lab

Build a small hub-and-branch network to master default static routes and the gateway of last resort. Each branch uses a default route toward the hub; the hub holds specific routes back to branch LANs. Verify routing tables and end-to-end host connectivity, then troubleshoot common misconfigurations.

Learning objectives

• Configure a default static route (gateway of last resort) on branch routers.
• Configure specific static routes to branch LANs on the hub router.
• Verify route installation with show commands and interpret the gateway of last resort.
• Validate host-to-host connectivity across the hub-and-branch topology.
• Troubleshoot missing default routes, wrong next-hops, and interface/address issues.

Troubleshooting focus

• Verify every link's interface status and IP addressing (`show ip interface brief`) and correct any interface that is down or misaddressed.
• Confirm each device's running configuration matches the lab objective, and bring any interface, route, or service that is not in its expected state back to health.
• Trace end-to-end reachability with ping/traceroute and isolate the first hop where forwarding fails.