Command
Switchport Trunk Encapsulation isl
Use
Enables ISL trunking encapsulation on the interface.
Syntax
Switch(config-if)#switchport trunk encapsulation isl
Example
In this example, isl trunk encapsulation is enabled SW3’s fa0/2.
SW3(config)#int fa0/2 SW3(config-if)#switchport trunk encapsulation isl
Next, the trunk information is displayed for SW3.
SW3(config-if)#do show interface trunkPort Mode Encapsulation Status Native vlan 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 Fa0/20 1-4094 Fa0/21 1-4094 Fa0/22 1-4094 Port Vlans allowed and active in management domain Fa0/20 1,10-20,55,99,555 Fa0/21 1,10-20,55,99,555 Fa0/22 1,10-20,55,99,555 Port Vlans in spanning tree forwarding state and not pruned Fa0/20 none Fa0/21 1,10-11 Fa0/22 none