78 MSTP overview
MSTP overview
MSTP definition IEEE 802.1s, Multiple Spanning Tree Protocol (MSTP), supports multiple
instances of Spanning Tree to efficiently channel VLAN traffic over different
interfaces.
Each instance of the spanning tree behaves in the manner specified in IEEE
802.1w, Rapid Spanning Tree (RSTP), which specifies the rapid transitioning of
the port to the Forwarding state.
MSTP and other
spanning tree
protocols
The difference between the RSTP and the traditional STP (IEEE 802.1d) is the
ability of RSTP to configure and recognize full-duplex connectivity and ports
that are connected to end stations, resulting in rapid transitioning of the port to
the forwarding state and the suppression of Topology Change Notifications
(TCNs). These features are represented by the Edge Port and Point to Point
values. MSTP is compatible to both RSTP and STP. It behaves appropriately to
STP and RSTP bridges.
An MSTP bridge can be configured to behave entirely as a RSTP bridge or STP
bridge. Therefore, an IEEE 802.1s bridge inherently also supports IEEE 802.1w
and IEEE 802.1d.
Defaults
ā Support for MSTP operation is enabled by default.
ā STP functionality is enabled on all ports by default.
ā The common and internal spanning tree (CIST) instance (MSTID = 0) is the
only default MSTP instance.
For additional default values, see the CN1610 Network Switch CLI Command
Reference.
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