How Mstp Operates; Mst Regions - HP procurve 8100fl series Management And Configuration Manual

Spanning-Tree Operation
802.1s Multiple Spanning Tree Protocol (MSTP)
N o t e
9-8

How MSTP Operates

In the factory default configuration, spanning tree operation is off. Also, the
switch retains its currently configured spanning tree parameter settings when
disabled. Thus, if you disable spanning tree, then later re-enable it, the
parameter settings will be the same as before spanning tree was disabled.
The switch automatically senses port identity and type, and automatically
defines spanning-tree parameters for each type, as well as parameters that
apply across the switch. Although these parameters can be adjusted, ProCurve
strongly recommends leaving these settings in their default configurations
unless the proposed changes have been supplied by an experienced network
administrator who has a strong understanding of the IEEE 802.1D/w/s
standards and operation.

MST Regions

All MSTP switches in a given region must be configured with the same VLANs.
Also, each MSTP switch within the same region must have the same VLAN-to­
instance assignments. (A VLAN can belong to only one instance within any
region.) Within a region:
■ All of the VLANs belonging to a given instance compose a single, active
spanning-tree topology for that instance.
■ Each instance operates independently of other regions.
Between regions there is a single, active spanning-tree topology.
How Separate Instances Affect MSTP Operation. Assigning different
groups of VLANs to different instances ensures that those VLAN groups use
independent forwarding paths. For example, in figure 9-3 each instance has a
different forwarding path.