Command
Switchport Trunk Encapsulation dot1q
Use
Enables dot1q trunking encapsulation on the interface.
Syntax
Switch(config-if)#switchport trunk encapsulation dot1q
Example
First, here is the trunking information for SW3. Note fa0/19, which is set to ISL.
SW3(config-if)#do show int trunkPort Mode Encapsulation Status Native vlan Fa0/19 auto isl trunking 1 Fa0/20 auto n-802.1q trunking 1 Fa0/21 auto n-802.1q trunking 1 Fa0/22 auto n-802.1q trunking 1 Port Vlans allowed on trunk Port Vlans allowed and active in management domain Port Vlans in spanning tree forwarding state and not pruned |
Next, dot1q trunking is enabled on fa0/2 on SW3.
SW3(config)#int fa0/2 |
Here is the trunking information after making the changes.
SW3(config-if)#do show int trunkPort Mode Encapsulation Status Native vlan Fa0/19 auto 802.1q trunking 1 Fa0/20 auto n-802.1q trunking 1 Fa0/21 auto n-802.1q trunking 1 Fa0/22 auto n-802.1q trunking 1 Port Vlans allowed on trunk Port Vlans allowed and active in management domain Port Vlans in spanning tree forwarding state and not pruned Port Vlans in spanning tree forwarding state and not pruned |