There are a lot of ways to accomplish that without a new feature. If it is a switch port, simply configure it as an access port with an undefined vlan. Routed ports even eaiser no ip address. Or is there some reason these techniques would not work.
I dont understand the statement. It seems that your feature would a) not pass any real traffic and b) automatically shut the port back down. While my suggestion would not accomdate b), when could you do your test cdp command but not do switchport access vlan 999 no shut, as your stated suggestion requires access to the device CLI remotely or not.
I've requested a link between Switch 1 and Switch 2. The subcontractor made a mistake and laid the cable between Switch 1 and Switch 22. I configure the switchports on Switch 1 and Switch 2, bring up the interfaces, then nothing happens.
Your solution wouldn't help in this case, because I don't know where the cable is connected. I can't set all unused ports on all switches to find it, and I don't want to risk creating a loop or other issues.