4 hands-on WAN scenarios you build in your own Cisco Modeling Labs instance and grade against the answer key. WAN configuration and troubleshooting practice for CCNA.
A late-night rollback restored configs from before a WAN carrier change. Since then, both branches report OSPF neighbors that appear, start exchanging, and then reset—never reaching FULL. Users at Branch A cannot reach Branch B. Your task is to observe the partial adjacency behavior, isolate why the database exchange never completes, and restore the carrier’s standard everywhere it applies so reachability returns end-to-end.
Two sites have dual WAN links (primary and backup). Both circuits are up and end-to-end connectivity works, yet every intersite flow rides the slow backup path. Your job: read which routes each router actually installed for the opposite site and why, then restore the intended path preference so traffic uses the primary circuit while keeping the backup standing by.
A replacement branch router came up on three carrier handoffs. All subinterfaces and /30s look correct and line protocols are up, yet no traffic passes. Your job: read what each circuit actually puts on the wire and bring the branch into alignment with the remote ends — including the carrier-published IP MTU on one circuit — without altering addressing or static routes.
Advanced static-routing capstone, run as a fault hunt. Two suites were cut over last night and now Suite-B is unreachable, Suite-A gets replies only sometimes, and one client cannot even reach its own gateway. Nothing was written down. You get symptoms and the required end state — no fault list. The faults span both routers and the access switch, and the routing table being present does not mean it is right.
