An engineer must configure switch port 5/1 to send CDP packets to configure an attached Cisco IP phone to trust tagged traffic on it's access port. Which command is required to complete the…

Specifying a CoS value like cos 3 or cos 5 with platform qos trust extend is not the standard command to simply enable the phone to trust traffic on its access port; the base command handles the trust extension.

The platform qos trust extend command, when configured on a switch port, enables the switch to send CDP messages to the connected Cisco IP phone, instructing the phone to trust the CoS markings on incoming frames from its connected PC port. This allows end-to-end QoS for the phone and any attached device.

platform qos extend trust is an incorrect command syntax.

Specifying a CoS value like cos 3 or cos 5 with platform qos trust extend is not the standard command to simply enable the phone to trust traffic on its access port; the base command handles the trust extension.