Overview - HP procurve 8100fl series Management And Configuration Manual

Spanning-Tree Operation

Overview

N o t e
9-2

Overview

Spanning tree is used to prevent network loops. Without spanning tree it is
possible to have more than one active path to a destination, which can result
in duplication of messages, leading to a "broadcast storm" that can bring down
the network. This chapter describes the application of the Multiple Spanning-
Tree Protocol (MSTP) on the 8100fl switch, and how to configure it using the
CLI. MSTP extends the Spanning Tree Protocol (STP) and the Rapid Spanning
Tree Protocol (RSTP) and is backwards compatible with both versions.
For more information on interoperability with RSTP and STP devices, see
"Transitioning from STP or RSTP to MSTP" on page
MSTP Features
802.1s Spanning Tree Protocol
Viewing MSTP Status and Configuration
Enable/Disable MSTP and Configure
Global Parameters
Configuring Basic Port Connectivity
Parameters
Configuring MSTP Instance Parameters
Configuring MSTP Instance Per-Port
Parameters
Enabling/Disabling MSTP Operation
Multiple-Instance spanning tree operation (802.1s) ensures that only one
active path exists between any two nodes in a spanning-tree instance. A
spanning-tree instance comprises a unique set of VLANs, and belongs to a
specific spanning-tree region. A region can comprise multiple spanning-tree
instances (each with a different set of VLANs), and allows one active path
among regions in a network. Applying VLAN tagging to the ports in a multiple-
instance spanning-tree network enables blocking of redundant links in one
instance while allowing forwarding over the same links for non-redundant use
by another instance.
9-13.
Default
n/a
Disabled
edge-port: No
mcheck: Yes
hello-time: 2
path-cost: auto
point-to-point MAC: Force-True
priority: 128 (multiplier: 8)
instance (MSTPI): none
priority: 32768 (multiplier: 8)
Auto
Disabled
Page Ref
page 9-28
page 9-17
page 9-19 and
following
page 9-22
page 9-25
page 9-27