Vlan and ports

Good day all

Sorry all kind of embarrassed to ask this question but here we go…on a switch what is the technical term for ports assigned to vlans that don’t exists? I was going to say unassigned ports but that doesn’t seemed technical and so far I haven’t been able to find a technical term for that.

Thank you in advance!!

Hello Warren

Hmm, I’m not familiar with an official term used exclusively for such a situation. I would call such ports orphaned ports or ports assigned to non-existent VLANs :stuck_out_tongue: . Actually, it’s kind of difficult to create such a scenario where you have a port assigned to a VLAN that doesn’t exist.

On a Cisco switch, if you assign a port to a VLAN that has not been created yet, the device will automatically create it for you:

SW1(config)#interface gigabitethernet 0/2
SW1(config-if)#switchport access vlan 20
% Access VLAN does not exist. Creating vlan 20
SW1(config-if)#

You must then delete the VLAN from the VLAN database, and only then will Gi0/2 be assigned to a non-existent VLAN.

I hope this has been helpful!

Laz

Is that not the Default VLan? or 1. Unless I misread the query

Hello Michael

By default, all ports on a switch are access ports and are assigned to the default VLAN which is indeed VLAN1. However, it is possible to assign a VLAN to a port, say VLAN 20, and then delete the VLAN from the VLAN database. The result is a port assigned to a VLAN that doesn’t exist. You cannot do that with VLAN 1 because you cannot delete VLAN 1. Does that make it clearer?

I hope this has been helpful!

Laz