What must be configured to resolve the issue?

An engineer configured a DHCP server for Cisco IP phones to download its configuration from a TFTP server, but the IP phones failed to toad the configuration.

What must be configured to resolve the issue?
A . BOOTP port 67
B . DHCP option 66
C . BOOTP port 68
D . DHCP option 69

Answer: B

Explanation:

DHCP options 3, 66, and 150 are used to configure Cisco IP Phones. Cisco IP Phones download their configuration from a TFTP server. When a Cisco IP Phone starts, ifit does not have both the IP address and TFTP server IP address preconfigured, it sends a request with option 150 or 66 to the DHCP server to obtain this information.

+ DHCP option 150 provides the IP addresses of a list of TFTP servers.

+ DHCP option 66 gives the IP address or the hostname of a single TFTP server.

Reference: http://www.cisco.com/c/en/us/td/docs/security/asa/asa84/configuration/guide/asa_84_cli_config/basic_dhcp.pdf