Core issue
The VLAN interfaces have to fulfill these general conditions to be up/up:
- The VLAN exists and is in active status on the switch VLAN database.
- The VLAN interface exists on the switch and is not administratively down.
- At least one Layer 2 (L2) (access port or trunk) port exists and has a link up on this VLAN.
- At least one L2 (access port or trunk) port is in spanning-tree forwarding state on the VLAN.
- At least one device is connected to an interface in that particular VLAN.
Resolution
Connect a device to an interface in that particular VLAN to bring the interface up.
For more information on troubleshooting a VLAN interface in up/down or down/down status, refer to Understanding and Troubleshooting the Autostate Feature in Catalyst Switches.