Implementing and Operating Cisco Collaboration Core Technologies (CLCOR) — Question 15

Which configuration tells a switch port to send Cisco Discovery Protocol packets that configure an attached Cisco IP phone to trust tagged traffic that is received from a device that is connected to the access port on the Cisco IP phone?

Answer options

• A. Router# configure terminal Router(config)# interface gigabitethernet 5/1 Router(config-if)# platform qos trust extend
• B. Router# configure terminal Router(config)# interface gigabitethernet 5/1 Router(config-if)# platform qos trust extend cos 3
• C. Router# configure terminal Router(config)# interface gigabitethernet 5/1 Router(config-if)# platform qos trust extend cos 5
• D. Router# configure terminal Router(config)# interface gigabitethernet 5/1 Router(config-if)# platform qos extend trust

Correct answer: A

Explanation

The correct configuration is option A, which sets the port to trust all tagged traffic by using the command 'platform qos trust extend'. Options B and C specify a Class of Service (CoS) value that restricts trusted traffic to only those with a specific CoS, which is not what is needed for all tagged traffic. Option D is incorrect as it lacks the 'trust extend' command necessary for this specific configuration.