I've read that when configuring MSTP you should not map VLANs to instance 0. Is this true only when there are multiple regions or also in single region configuration? The meaning of IST is not very clear for me. If there are no VLANs mapped to instance 0, which VLAN carries the BPDU packets, or is it even possible that there are no VLANs in instance 0?
-Sam