> Not if they're doing it right. Access ports, ports that apply and remove the tag upon ingress and egress, should only accept untagged frames and should reject anything that comes with one.
That is what was worrying me. Good to hear. So much written about VLANs is waffle, not very explicit and full of jargon that is rather variable too. "i just want to know what happens to 802.1q tags in some cases and a lot of docs, manuals, videos etc don't just give you that answer - it get added / removed / replaced / blocked / allowed - straight.