You configured VLAN on an interface, but it is not working. After looking at the VLAN database, you find it has been disabled. Which command will enable the VLAN?

The proper way to enable a VLAN to forward traffic is to first enter the VLAN database for ID 3 and then issue the no shutdown command. On some IOS versions, this can also be done via the command no shutdown vlan 3 from global config mode. The command enable vlan 3 configured in privilege exec mode is not a valid command. The command enable vlan 3 configured in global configuration is not a valid command. Although the command no shutdown vlan 3 is valid on some IOS versions, it must be configured from global configuration mode.