The branch office can't reach the internet
A stub site has no way out. Everything internal works, but nothing beyond the edge is reachable. Add the route that fixes it.
Scenario
A small branch office sits behind R1. R1 connects up to the edge router R2, which is your way to everything outside. Call it "the internet" (the outside host stands in for it). Hosts on the branch LAN can reach R1 fine, and R1 and R2 can ping each other across their link. But host-A can't reach anything beyond R1.
R2 already knows how to get back to the branch LAN. The branch side is what's missing a way out.
Topology
- host-A
10.0.1.10/24→ gateway R110.0.1.1 - R1 ↔ R2 link: R1
100.64.0.1/30, R2100.64.0.2/30 - Outside host
203.0.113.10/24, reached through R2 (203.0.113.1)
Your job
Give the branch a way out. host-A should be able to reach the outside host, without changing any IP addressing.
What "done" looks like
host-A reaches 203.0.113.10, and R1's table shows a default route pointing at R2.
Teaches: a stub site doesn't need every route; it needs one default pointing at its exit. And the exit router needs a route back for the replies to return.
What gets checked
Your solution is verified against each of these:
- R1 has a default route (0.0.0.0/0) pointing at the edge router
- Ping from host-A (10.0.1.10) to the outside host (203.0.113.10) succeeds
Solve it in the browser lab
No setup, no install. Open a live lab: configure each device in the editor or its Cisco IOS terminal, run show/ping/traceroute (or test from the hosts), and watch the network react. The in-house engine grades your fix instantly and issues your proof the moment every check passes.
Open the lab →Prefer your own lab?
- Build the fix locally. New to the tooling? See setting up your lab.
- Push your topology file, device configs, and any playbooks to a public repo (GitHub or GitLab).
- Submit the repo link. We review it by hand, confirm it works, and issue your proof page.