DNS is configured to respond with a list containing multiple controller addresses.
Upon DNS discovery, which statement is true?
Click on the arrows to vote for the correct answer
A. B. C. D.C.
When an Access Point (AP) joins a Wireless LAN (WLAN), it needs to discover a Wireless LAN Controller (WLC) to connect to. One way to provide the WLC IP address to the AP is to configure DNS with a list of multiple WLC IP addresses. In this scenario, upon DNS discovery, the AP must determine which WLC to connect to.
The correct answer is A. The AP sends a discovery request to the first controller on the list, and then goes down the list chronologically until it receives a discovery response.
When the AP receives the DNS response with a list of multiple WLC IP addresses, it selects the first IP address on the list and sends a discovery request to that controller. If the first controller responds with a discovery response, the AP stops the discovery process and connects to that controller. If the first controller does not respond, the AP sends a discovery request to the next controller on the list and continues down the list chronologically until it receives a discovery response.
Option B is incorrect because the AP does not start with the last controller on the list and work its way up chronologically. It starts with the first controller and works its way down chronologically.
Option C is incorrect because the AP does not send a discovery request to all controllers on the list simultaneously. It sends a request to one controller at a time.
Option D is incorrect because multiple controller IP addresses in a DNS response are supported and can be useful for providing redundancy and load balancing across multiple WLCs.
In summary, when DNS is configured to respond with a list containing multiple controller addresses, the AP sends a discovery request to the first controller on the list, and then goes down the list chronologically until it receives a discovery response.