CISCO CCNA 200-301 Q58

Which command is used on the Cisco Catalyst 2950 series switch to configure a port as a VLAN trunk port?.

A. switchport mode trunk
B. set trunk on
C. switchport trunk on
D. trunk mode on

Correct Answer: A

Explanation:
The switchport mode trunk command is used on the Cisco Catalyst 2950 switch to configure a port as a VLAN trunk port. The syntax of the command is as follows:

Switch(config-if)# switchport mode trunk

Trunk links are required between devices in any situation where traffic from multiple VLANs will traverse the link. This is also true when using VTP on the switches
and in that case, even if inter-VLAN routing is not required. For example, if two switches in a VTP domain are connected together via an access link with no router present, then when you create a new VLAN on one of the switches, it will NOT be learned by the other switch.

When you configure a trunk link, there are two choices for encapsulation: 802.1q, which is the industry standard, and ISL, which is Cisco proprietary and will only work when both ends are Cisco equipment. Both protocols perform a crucial role in inter-VLAN routing by tagging packets with the VLAN to which the packets belong.