Question 390
Following remediation at a regional data center, engineers revisit: A branch's hide NAT pool runs out of usable port resources during peak connections, causing new sessions to fail while existing ones work. Which observation would BEST prove the specific issue is resolved?
Explanation
Correct Answer
Peak-load tests establish new connections without NAT resource exhaustion warnings. This evidence directly tests the intended corrective action: Assess supported DIPP capacity and allocate an appropriately sized translated address pool or reduce session pressure. It confirms the failure mechanism—Port-based many-to-one source NAT has finite translated address and port resources.—has been addressed in the actual affected flow.
Incorrect Answers
A sample session is mapped to its internal origin and observed public egress address. This would verify resolution of a different case: A proxy monitoring report counts only untranslated source addresses while the compliance team tries to identify who used a shared public source NAT IP. It does not show that the reported issue was fixed or that its intended action—Assess supported DIPP capacity and allocate an appropriately sized translated address pool or reduce session pressure.—worked.
Return packets reach the firewall and test sessions establish bi-directionally. This would verify resolution of a different case: The outside NAT address is included in a pool but the ISP does not route return packets to the firewall, so outbound sessions time out. It does not show that the reported issue was fixed or that its intended action—Assess supported DIPP capacity and allocate an appropriately sized translated address pool or reduce session pressure.—worked.
Public requests reach the new private target and legitimate sessions return without asymmetric failure. This would verify resolution of a different case: 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 does not show that the reported issue was fixed or that its intended action—Assess supported DIPP capacity and allocate an appropriately sized translated address pool or reduce session pressure.—worked.