Question 470
Following remediation at a research campus, engineers revisit: A remote branch allows internal clients to access a web service via its public VIP, but hairpin requests fail because required U-turn NAT is absent. Which observation would BEST prove the specific issue is resolved?
Explanation
Correct Answer
An internal client resolves the public name and reaches the approved internal server without asymmetric routing. This evidence directly tests the intended corrective action: Configure the supported hairpin source and destination translation path with correct security and routing controls. It confirms the failure mechanism—Internal-to-public-VIP flows can need distinct translation and return-path treatment.—has been addressed in the actual affected flow.
Incorrect Answers
The server logs the original permitted client source address and connections still reach the service. This would verify resolution of a different case: An inbound customer service needs the client IP preserved for server logs, but the administrator unnecessarily source-NATs every inbound request. It does not show that the reported issue was fixed or that its intended action—Configure the supported hairpin source and destination translation path with correct security and routing controls.—worked.
IPv6 test connections follow the intended approved path without falsely relying on IPv4 NAT. This would verify resolution of a different case: An engineer creates an IPv4 source NAT policy for an IPv6-only service path and assumes the same rule will translate both address families. It does not show that the reported issue was fixed or that its intended action—Configure the supported hairpin source and destination translation path with correct security and routing controls.—worked.
Finance test flows use the approved translated address and ordinary traffic retains its original egress NAT. This would verify resolution of a different case: An administrator copies a source NAT rule above a more specific exception, causing sensitive finance flows to leave through the wrong public IP. It does not show that the reported issue was fixed or that its intended action—Configure the supported hairpin source and destination translation path with correct security and routing controls.—worked.