Simplified TRUNK formation

TRUNK port is to allow multi-VLANs in a network port.
ACCESS port is to allow a single VLAN in a network port.

Switchport trunk encapsulation dot1q !IEEE standard

Switchport trunk encapsulation ISL !Cisco proprietary

to verify...
Cat2#show interface gi0/11 switchport 
Name: Gi0/11
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: On

switchport mode trunk

switchport mode dynamic desirable

switchport mode dynamic auto