Chapter 1
Configuring STP
Spanning-Tree Interoperability and Backward Compatibility
Table 1-2
network.
Table 1-2
PVST+
MSTP
Rapid PVST+
In a mixed MSTP and PVST+ network, the common spanning-tree (CST) root must be inside the MST
backbone, and a PVST+ switch cannot connect to multiple MST regions.
When a network contains switches running rapid PVST+ and switches running PVST+, we recommend
that the rapid-PVST+ switches and PVST+ switches be configured for different spanning-tree instances.
In the rapid-PVST+ spanning-tree instances, the root switch must be a rapid-PVST+ switch. In the
PVST+ instances, the root switch must be a PVST+ switch. The PVST+ switches should be at the edge
of the network.
All stack members run the same version of spanning tree (all PVST+, all rapid PVST+, or all MSTP).
OL-25303-03
lists the interoperability and compatibility among the supported spanning-tree modes in a
PVST+, MSTP , and Rapid-PVST+ Interoperability
PVST+
Yes
Yes (with restrictions)
Yes (reverts to PVST+)
MSTP
Yes (with restrictions)
Yes
Yes (reverts to PVST+)
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
Understanding Spanning-Tree Features
Rapid PVST+
Yes (reverts to PVST+)
Yes (reverts to PVST+)
Yes
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