encapsulation mode

Using STP, you can configure ports within an STPD to accept specific BPDU encapsulations. The three encapsulation modes are:
  • 802.1D—This mode is used for backward compatibility with previous STP versions and for compatibility with third-party switches using IEEE standard 802.1D.
  • EMISTP—Extreme Multiple Instance Spanning Tree Protocol mode is an extension of STP that allows a physical port to belong to multiple STPDs by assigning the port to multiple VLANs.
  • PVST+—This mode implements PVST+ in compatibility with third-party switches running this version of STP.