Network challengecore4 devicespar 5:00
The OSPF neighbours that never meet
Two routers run OSPF over a working link, yet neither learns a single route. Get the adjacency to FULL.
The ticket
"The new branch router is cabled and OSPF is configured on both ends, but the branch still can't reach head office. The link itself pings fine." — branch rollout
Your goal: Bring R1 and R2 to an OSPF FULL adjacency so PC1 reaches the Server.
No sign-up · the clock starts when you press Start
The network you're handed
- R1 — a router, the branch router
- R2 — a router, the head-office router
- PC1 — a pc, a branch desk
- Server — a server, the head-office server
It is already cabled and configured, and something in it is wrong. Nothing on this page tells you what — find it the way an engineer would, with show commands, ping and ipconfig in the industry-standard CLI.
How it's scored
- The grader checks the real network, not your commands: the simulator runs the actual pings and reads the actual tables. It passes the moment every check holds.
- One star for fixing it, one for beating the par time of 5:00, one for using 12 commands or fewer.
- A quick fix that breaks something else doesn't count — the checks also watch what must stay working (or stay blocked).
- Your copy of the network is private to your browser. Share your score and a friend gets their own fresh copy.
Skills: OSPF · Dynamic routing · Troubleshooting
Stuck? The theory behind it
Next challenge: The ACL that blocks the wrong person