HP procurve 8100fl series Management And Configuration Manual page 123

C a u t i o n
MSTI (Multiple Spanning Tree Instance): This type of configurable
■
spanning tree instance comprises all static VLANs you specifically assign
to it, and must include at least one VLAN. The VLAN(s) you assign to an
MSTI must initially exist in the IST instance of the same MST region. When
you assign a static VLAN to an MSTI, the switch removes the VLAN from
the IST instance. (Thus, you can assign a VLAN to only one MSTI in a given
region.) All VLANs in an MSTI operate as part of the same single spanning
tree topology. (The switch does not allow dynamic VLANs in an MSTI.)
MSTP (Multiple Spanning Tree Protocol): A network supporting MSTP
allows multiple spanning tree instances within configured regions, and a
single spanning tree among regions, STP bridges, and RSTP bridges.
MSTP BPDU (MSTP Bridge Protocol Data Unit): These BPDUs carry
region-specific information, such as the region identifier (region name and
revision number). If a switch receives an MSTP BPDU with a region identifier
that differs from its own, then the port on which that BPDU was received is
on the boundary of the region in which the switch resides.
MSTP Bridge: In this manual, an MSTP bridge is a 8100fl switch (or another
802.1s-compatible device) configured for MSTP operation.
MST Region: An MST region comprises the VLANs configured on physically
connected MSTP switches. All switches in a given region must be configured
with the same VLANs and Multiple Spanning Tree Instances (MSTIs). The MST
region forms a multiple spanning tree domain and is a component of a single
spanning-tree domain within a network. For switches internal to the MST
region:
All switches have identical MST configuration identifiers (region name
■
and revision number).
All switches have identical VLAN assignments to the region's IST and
■
(optional) MST instances.
■ One switch functions as the designated bridge (IST root) for the region.
No switch has a point-to-point connection to a bridging device that cannot
■
process RSTP BPDUs.
When you enable MSTP on the switch, the default MSTP spanning tree
configuration settings comply with the values recommended in the IEEE
802.1s MSTP standard. Note that inappropriate changes to these settings can
result in severely degraded network performance. For this reason, ProCurve
strongly recommends that changing these default settings be reserved only
for experienced network administrators who have a strong understanding
of the IEEE 802.1D/w/s standards and operation.
Spanning-Tree Operation
802.1s Multiple Spanning Tree Protocol (MSTP)
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