Question 360
During a post-incident review at a logistics office, the original problem was: A public web application uses a private address but the NAT rule translates the wrong inbound public IP, sending clients to an old server. Which preventive practice most directly addresses its cause?
Explanation
Correct Answer
Reconcile public VIP changes with NAT and Security policy in a single change record. This control reduces recurrence of the documented mechanism: Incorrect destination NAT objects send traffic to the wrong internal endpoint. It creates a repeatable check around the needed response: Update the inbound destination NAT mapping and verify the accompanying Security policy matches the original public destination as supported.
Incorrect Answers
Reconcile NAT entries with asset retirement and Security-rule removal. That safeguard addresses another potential failure: A temporary DNAT rule remains enabled after a support tool is retired, exposing a legacy test host to the Internet. It is not the most targeted recurring control for the described cause: Incorrect destination NAT objects send traffic to the wrong internal endpoint.
Include backend health and return-path checks in DNAT change approval. That safeguard addresses another potential failure: A server migration retains the same public IP but changes the private destination; the NAT rule is edited while its backend health dependencies are ignored. It is not the most targeted recurring control for the described cause: Incorrect destination NAT objects send traffic to the wrong internal endpoint.
Validate partner source-IP contracts before selecting NAT method. That safeguard addresses another potential failure: An inside subnet must use one stable public egress IP for a partner allow-list but its NAT rule uses a dynamic interface address that changes. It is not the most targeted recurring control for the described cause: Incorrect destination NAT objects send traffic to the wrong internal endpoint.