Remote access: A new service prefix never reaches clients
The incident
Managed remote clients reach access-service gateways over an enterprise transit chain; unmanaged devices use a separate branch. The core has two routed branches and a cross-link before the common service handoff. BGP carries the primary service prefix, but the connected secondary service subnet is absent from remote BGP tables. Investigate access gateway transport from R1: 10.180.0.0/24 to 10.180.8.0/24 (TCP/443), and 10.180.1.0/24 to 10.180.9.0/24 (UDP/1194).
Your objective
Restore both authorized service transports and return reachability, including clients and service hosts in both halves of the primary subnet. Keep R2 blocked from both service transports, keep SSH blocked to both service subnets, and preserve monitoring between R1 and R3. Do not change physical topology or addressing. These are network forwarding checks, not application-level transactions.
The network
Link addressing (6)
- R1 R2
10.180.16.0/30 - R1 R3
10.180.17.0/30 - R2 R4
10.180.18.0/30 - R3 R4
10.180.19.0/30 - R2 R3
10.180.20.0/30 - R4 R5
10.180.21.0/30
What you’ll practice
Interview exercises are inspired by common industry competencies. They are not proprietary interview questions.