In STP (Spanning Tree Protocol), protected VLANs are the other (other than the carrier VLAN) VLANs that are members of the STPD (Spanning Tree Domain) but do not define the scope of the STPD. Protected VLANs do not transmit or receive STP BPDU (Bridge Protocol Data Unit)s, but they are affected by STP state changes and inherit the state of the carrier VLAN. Also known as non-carrier VLANs, they carry the data traffic.
In EAPS (Extreme Automatic Protection Switching), a protected VLAN is a VLAN that carries data traffic through an EAPS domain. You must configure one or more protected VLANs for each EAPS domain. This is also known as a data VLAN.