Data center: The new service host fails its network check
The incident
Application workers connect to database and connection-pool subnets through separate access and service aggregation layers. Independent north and south core paths connect the ingress and egress routers. The primary service transport succeeds to .10 but fails to .200 in the same destination subnet. ICMP to both addresses still works. Investigate database connectivity from R1: 10.168.32.0/24 to 10.168.42.0/24 (TCP/5432), and 10.168.33.0/24 to 10.168.43.0/24 (TCP/6432).
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 (6)
- R1 R2
10.168.48.0/30 - R2 R3
10.168.49.0/30 - R2 R4
10.168.50.0/30 - R3 R5
10.168.51.0/30 - R4 R5
10.168.52.0/30 - R5 R6
10.168.53.0/30
What you’ll practice
Interview exercises are inspired by common industry competencies. They are not proprietary interview questions.