Question 1070
At Newbridge Charity, a team reports that it corrected the following problem affecting donation applications and volunteer accounts: An access switch port allows unauthenticated clients onto a production VLAN when 802.1X fails. Which observation BEST verifies that the correction actually worked?
Explanation
Correct Answer
An unauthorized test device cannot enter the production VLAN after authentication failure. This is the decisive evidence for the original problem: An access switch port allows unauthenticated clients onto a production VLAN when 802.1X fails. It verifies that the intended corrective control—Configure closed or appropriately restricted authentication behavior with an explicit fallback design—works in the relevant environment; a completed change ticket alone would not prove the outcome at Newbridge Charity.
Incorrect Answers
A spoofed unknown endpoint cannot obtain privileged user-network resources. This would be relevant evidence for a different failure: An access policy grants privileged access based only on a claimed device MAC address, usually addressed by Combine MAB with profiling, segmentation, and stronger identity controls where possible. It does not demonstrate that the current problem at Newbridge Charity was resolved. The specific required evidence is: An unauthorized test device cannot enter the production VLAN after authentication failure.
Valid employees receive enterprise access and failed or guest sessions receive only restricted access. This would be relevant evidence for a different failure: An organization has separate employee and guest policies but the switch incorrectly falls back to guest VLAN for every failed login, usually addressed by Correct authentication method ordering and authorization fallback conditions. It does not demonstrate that the current problem at Newbridge Charity was resolved. The specific required evidence is: An unauthorized test device cannot enter the production VLAN after authentication failure.
802.1X requests reach the new ISE node and successful authentications are logged. This would be relevant evidence for a different failure: The switch sends RADIUS to an old ISE address and all port authentication times out after a server migration, usually addressed by Update the network device AAA server configuration and confirm reachability and shared secret. It does not demonstrate that the current problem at Newbridge Charity was resolved. The specific required evidence is: An unauthorized test device cannot enter the production VLAN after authentication failure.