INCIDENT #078 · SECURITY
The reverse path has its own security boundary
Hard25 minutesPro lab
The incident
The application-side router receives client traffic, but its ICMP return path toward 10.158.10.1 is denied. SSH initiated toward the client network must stay blocked.
Your objective
Restore the documented application transport flows and return reachability. Keep SSH blocked, preserve the working telemetry branch, and do not remove security boundaries or change interface addresses.
The network
Physical links · Service health not shown
Link addressing (3)
- R1 R2
10.158.12.0/30 - R2 R3
10.158.23.0/30 - R2 R4
10.158.24.0/30
4 devices · Cisco IOS syntax · Simulated network
What you’ll practice
Interview exercises are inspired by common industry competencies. They are not proprietary interview questions.