Encapsulation Modes

You can configure ports within an STPD to accept specific BPDU encapsulations.

This STP port encapsulation is separate from the STP mode of operation. For example, you can configure a port to accept the PVST+ BPDU encapsulation while running in 802.1D mode.

An STP port has three possible encapsulation modes:

These encapsulation modes are for STP ports, not for physical ports. When a physical port belongs to multiple STPDs, it is associated with multiple STP ports. It is possible for the physical port to run in different modes for different domains to which it belongs.

If configured in MSTP mode, an STPD uses the 802.1D BPDU encapsulation mode by default. To ensure correct operation of your MSTP STPDs, do not configure EMISTP or PVST+ encapsulation mode for MSTP STPDs.

Instead of accepting the default encapsulation modes of dot1d for the default STPD s0 and for all other STPDs, this command allows you to specify the type of BPDU encapsulation to use for all ports added to the STPD (if not otherwise specified).