Which DHCP option is used by Cisco wireless access points to get their WLC IP addresses?

The correct choice is based on the function of DHCP options in network configurations, specifically for Cisco wireless access points. Option 43 is utilized by Cisco wireless access points to communicate with Cisco Wireless LAN Controllers (WLC). When a wireless access point boots up and needs to locate its controller, it sends out a DHCP request. The DHCP server can then respond with Option 43, which contains the IP address of the WLC. This enables the access point to discover and register with the correct WLC, facilitating centralized management and configuration of the wireless network.

While other DHCP options also serve important roles, they do not fulfill this specific function. For instance, Option 150 is another option that some Cisco devices use for similar purposes, specifically defined for Cisco to convey TFTP server addresses, but it is not standard for access point-to-WLC communication. Options 60 and 55 serve different purposes entirely, with Option 60 being used for vendor class identifiers and Option 55 for parameter requests, which do not directly facilitate the discovery of a WLC. Thus, recognizing the correct usage of these DHCP options is essential for effectively managing Cisco wireless networks.