Common Production Failure Scenarios Questions

Candidates should be able to enumerate and diagnose common production network failure modes and to describe detection, mitigation, and prevention strategies. Representative scenarios include maximum transmission unit mismatches in tunnels and virtual private networks, domain name resolution failures, dynamic host configuration protocol exhaustion, port connectivity and interface errors, network address translation and firewall rule blockages, address resolution protocol conflicts, virtual local area network misconfiguration, asymmetric routing and black hole situations. For each type of failure describe typical telemetry and alerts, immediate mitigations and workarounds, diagnostic data sources and steps, impact assessment, and durable fixes such as configuration standards, automated testing, and monitoring improvements.