Comment 2 for bug 1552923

"So by "fixing" this bug, we would effectively be forcing users to model a single fabric as two fabrics - a showstopper issue that prevents any customers who have shared VLANs between the "two" fabrics from using MAAS."

You are correct that it will prevent users from performing an action that they should not be allowed to do. At the current state in time we do not support that mode of operation. So in reality by not "fixing" this bug, you are deliberaly accepting that a users experience with MAAS will be inconsistent and an overall bad UX. That is unacceptable.