DNS Lookup for CAPWAP Discovery | Cisco Exam 350-401-ENCOR

Access Point CAPWAP Discovery: DNS Lookup

Question

Which DNS lookup does an access point perform when attempting CAPWAP discovery?

Answers

Explanations

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A. B. C. D.

C.

http://www.revolutionwifi.net/revolutionwifi/2010/11/capwap-controller-discovery-process_23.html

When an access point (AP) is powered on or restarted, it needs to discover a wireless LAN controller (WLC) to join. To accomplish this, the AP uses the Control and Provisioning of Wireless Access Points (CAPWAP) protocol, which is a lightweight protocol designed to establish a secure tunnel between the AP and the WLC.

During the CAPWAP discovery process, the AP sends a Domain Name System (DNS) request to resolve the hostname of the WLC. The DNS lookup returns the IP address of the WLC, which the AP uses to establish a CAPWAP tunnel.

The default hostname used by Cisco Wireless LAN Controllers for CAPWAP discovery is CISCO-CAPWAP-CONTROLLER.local, which maps to the loopback address of the WLC. This hostname is configured in the WLC's DNS server or in a DHCP option, and it can be changed to a custom hostname if desired.

Therefore, the correct answer to the question is C. CISCO-CAPWAP-CONTROLLER.local. This is the default hostname used by Cisco WLCs for CAPWAP discovery, and the one that an AP will use by default if no other hostname is configured. The other answer choices, CISCO-CONTROLLER.local, CAPWAP-CONTROLLER.local, and CISCO-DNA-CONTROLLER.local, are not valid default hostnames for Cisco WLCs.