Core
Static Routing
Static routes are manually configured paths to remote networks, offering predictability and low overhead but requiring manual updates when the topology changes.
What you need to know
- Default administrative distance for a static route is 1 (5 if it specifies both an interface and floating behavior differs by IOS version, but standard is 1).
- A static route can point to a next-hop IP, an exit interface, or both.
- Using only an exit interface on a multi-access network can cause proxy-ARP overhead; next-hop IP is generally preferred there.
- A floating static route uses a higher administrative distance to act as a backup to a dynamic route.
- ip route 0.0.0.0 0.0.0.0 configures a default static route (gateway of last resort).
- Static routes remain in the routing table only while the referenced next hop or exit interface is up.
- Recursive lookups occur when a static route points only to a next-hop IP that itself must be resolved via another route.
Configuration commands
| Command | Mode | Purpose |
|---|---|---|
| ip route 172.16.1.0 255.255.255.0 10.0.0.2 | config | Configure a static route via a next-hop IP address. |
| ip route 172.16.1.0 255.255.255.0 gigabitethernet0/1 | config | Configure a static route via an exit interface. |
| ip route 172.16.1.0 255.255.255.0 10.0.0.2 200 | config | Configure a floating static route with administrative distance 200. |
| ip route 0.0.0.0 0.0.0.0 10.0.0.1 | config | Configure a default static route (gateway of last resort). |
| ip route 172.16.1.0 255.255.255.0 10.0.0.2 name BACKUP-LINK | config | Add a descriptive name to a static route entry. |
| no ip route 172.16.1.0 255.255.255.0 10.0.0.2 | config | Remove a previously configured static route. |
Verify it
- show ip route static
- show ip route
- show ip route 172.16.1.0
- ping 172.16.1.1
- traceroute 172.16.1.1
Common mistakes
- Pointing a static route to the wrong next hop, causing a routing loop.
- Forgetting a return-path static route on the remote router.
- Using an exit interface on a broadcast multi-access network causing excessive ARP traffic.
- Omitting the administrative distance on a floating static route so it wins over the dynamic route.
- Leaving a stale static route pointing to a next hop that no longer exists.
Practise Static Routing in a real CLI
Generated labs, graded against the simulated network state.