Static Routing Lab
Build a multi-router topology with static and default routes.
Objectives
- Cable three routers in a chain or triangle
- Configure point-to-point /30 WAN links
- Add static routes so all LANs are reachable
- Verify with show ip route and end-to-end ping
Topology
LAN-A ─ R1 ─ /30 ─ R2 ─ /30 ─ R3 ─ LAN-C. Each router has one LAN interface and one serial/WAN link.
Prerequisites
- Static routing lesson
- Subnetting /30 for WAN links
Instructions
Step 1
Address WAN and LAN interfaces
Use /30 subnets on each WAN link. Assign LAN gateways on each router LAN interface.
Router(config)# interface g0/0 Router(config-if)# ip address 192.168.1.1 255.255.255.0 Router(config-if)# no shutdown Router(config)# interface s0/0/0 Router(config-if)# ip address 10.0.12.1 255.255.255.252
Step 2
Static routes on R1
R1 knows its connected networks. Add static routes to remote LANs via next-hop IP on the WAN.
Router(config)# ip route 192.168.2.0 255.255.255.0 10.0.12.2 Router(config)# ip route 192.168.3.0 255.255.255.0 10.0.12.2
Step 3
Complete routing on R2 and R3
Each router needs paths to networks it does not directly connect. Use next-hop IPs, not exit interfaces, on multi-access-style WANs.
Router# show ip route Router# show ip route static
Step 4
Default route (optional)
On edge router, point unknown traffic to the ISP or hub with ip route 0.0.0.0 0.0.0.0 next-hop.
Router(config)# ip route 0.0.0.0 0.0.0.0 10.0.23.2
Verification checklist
- show ip route on each router lists C, S, and reachable remote LANs
- Ping from LAN-A host to LAN-C host succeeds
- Traceroute shows expected hop path
Troubleshooting
Remote LAN unreachable
Check static route next-hop is reachable; verify return path exists on the far router.
Serial link down
On DCE side set clock rate; no shutdown on both interfaces; correct cable type.