Backup network: Both services fail after route cleanup
The incident
Backup agents traverse a routed storage boundary while replication monitoring and a lab tenant share a separate branch. Every core router peers with the other three, between separate client and service handoffs. Both service subnets stopped responding after a route cleanup. Monitoring traffic still succeeds and the client route table is not empty. Investigate backup transport from R1: 10.174.32.0/24 to 10.174.42.0/24 (TCP/2049), and 10.174.33.0/24 to 10.174.43.0/24 (UDP/111).
Your objective
Restore both authorized service transports and return reachability, including clients and service hosts in both halves of the primary subnet. Keep R3 blocked from both service transports, keep SSH blocked to both service subnets, and preserve monitoring between R1 and R4. Do not change physical topology or addressing. These are network forwarding checks, not application-level transactions.
The network
Link addressing (8)
- R1 R2
10.174.48.0/30 - R2 R3
10.174.49.0/30 - R2 R4
10.174.50.0/30 - R2 R5
10.174.51.0/30 - R3 R4
10.174.52.0/30 - R3 R5
10.174.53.0/30 - R4 R5
10.174.54.0/30 - R5 R6
10.174.55.0/30
What you’ll practice
Interview exercises are inspired by common industry competencies. They are not proprietary interview questions.