Which three of these statements about Dynamic Trunking Protocol are correct? (Choose three.)
A.
It supports autonegotiation for both ISL and IEEE 802.1Q trunks.
B.
It must be disabled on an interface if you do not want the interface to work as a trunk or start negotiation to become a trunk.
C.
It is a point-to-multipoint protocol.
D.
It is a point-to-point protocol.
E.
It is not supported on private VLAN ports or tunneling ports.
Explanation:
switchport mode access – This command puts the interface (access port) into permanent nontrunking mode. The interface will generate DTP frames, negotiating with the neighboring interface to convert the link into a nontrunk link. The interface becomes a nontrunk interface even if the neighboring interface does not agree to the change.
switchport mode dynamic desirable – This command makes the interface actively attempt to convert the link to a trunk link. The interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode. This is the default mode for all Ethernet interfaces. If the neighboring interface is set to the access or non-negotiate mode, the link will become a non-trunking link.
switchport mode dynamic auto This command makes the interface willing to convert the link to a trunk link if the neighboring interface is set to trunk or desirable mode. Otherwise, the link will become a non-trunking link.
switchport mode trunk This command puts the interface into permanent trunking mode and negotiates to convert the link into a trunk link. The interface becomes a trunk interface even if the neighboring interface does not agree to the change.
switchport nonegotiate Prevents the interface from generating DTP frames. You can use this command only when the interface switchport mode is access or trunk. You must manually configure the neighboring interface as a trunk interface to establish a trunk link, otherwise the link will be a non-trunking link.Using these different trunking modes, an interface can be set to trunking or nontrunking or even able to negotiate trunking with the neighboring interface. To automatically negotiate trunking, the interfaces must be in the same VTP domain. Trunk negotiation is managed by the Dynamic Trunking Protocol (DTP), which is a Cisco proprietary Point-to-Point Protocol.