When we try to display the particular interface which contain VLAN encapsulation, there is no information on the VLAN ID under the interface.
1. We try to display the interface by using command:'display interface gigabitethernet X/X/X.X
2. There is a message shown 'VLAN number 1'.
3. This message does not indicate the VLAN ID that encapsulated under the interface, it is only the numbers/quantity of VLAN under the interface.
4. The only way to known what VLAN being encapsulated under the interface is by using 'display current-configuration'.
There should be a extra command line to display the VLAN that encapsulated under the VLAN, when the configuration files is very huge, using display current-configuration will not be suitable.