Switchport Trunk Encapsulation dot1q: Configure VLAN Tagging for Trunking

This command configures a switchport to use the IEEE 802.1Q encapsulation method for trunking. 802.1Q is a standard for VLAN tagging that allows multiple VLANs to be carried over a single physical link. This command must be used on both ends of the trunk link to ensure proper communication between devices.