Core issue
This status might be required when using Layer 3 (L3) routing.
Resolution
Normally, to maintain a VLAN in up/up state on a switch, you need to have at least one physical device connected in that VLAN. Otherwise, the VLAN has an up/down state. Currently, there is no command to put a VLAN interface up/up when there are no active ports in the switch for that VLAN.
If you do not want to connect a device, connect a loopback plug in any port for that VLAN. As an alternative, try a crossover cable that connects two ports in that VLAN on the same switch. This method forces the port up.
For more information, refer to the Loopback Plug section of Loopback Tests for T1/56K Lines.
