You have to assume an ont is rooted/third party when designing pon, this is pure bad design nothing more. OLT should inject vlans based on Mac/ID of the ONT+po

You have to assume an ont is rooted/third party when designing pon, this is pure bad design nothing more. OLT should inject vlans based on Mac/ID of the ONT+pon port, the only real vulnerability in ones I've designed is if someone on the same pon knows someone else's SN and thier service was subscribed but ont unplugged.