Huawei quidway s7700 - STP;RSTP Features Supported by the S7700

Spanning
Tree
Protocol
Characteristics Applicable
Environment
Precautions
MSTP
l In an MSTP region, a
loop-free tree is
generated. Thus,
broadcast storms are
prevented and
redundancy is
implemented.
l A feedback mechanism
is provided to confirm
topology convergence.
Thus, rapid
convergence is
implemented.
l MSTP implements
load balancing among
VLANs. Traffic in
different VLANs is
transmitted along
different paths.
User or service-specific
load balancing is
required. Traffic for
different VLANs is
forwarded through
different spanning
trees, which are
independent of each
other.
8.1.2 STP/RSTP Features Supported by the S7700
Before configuring STP/RSTP, familiarize yourself with the concepts of basic STP/RSTP
functions, topology convergence, STP/RSTP protection, and STP/RSTP interoperability
between Huawei devices and non-Huawei devices. This will help you complete the configuration
task quickly and accurately.
STP/RSTP is used to block redundant links on the Layer 2 network and trim a network into a
loop-free tree topology. The basic configuration roadmap of STP/RSTP is as follows:
1. Select a switching device (functioning as a root bridge) from switching devices for each
spanning tree. You can configure the priorities of the switching devices to preferentially
select a root bridge.
2. In each spanning tree, calculate the shortest paths from the other switching devices to the
root bridge, and select a root port for each non-root switching device. You can configure
the cost of the path from a switching device to the root bridge to preferentially select a root
port.
3. In each spanning tree, select a designated port for each connection according to the bridge
ID, the cost of path and port IDs. If the devices have the same bridge ID and the cost of
path, You can configure the port priorities to preferentially select a designated port.
STP/RSTP also supports the following features to meet requirements of special applications and
extended functions:
l A feedback mechanism is provided to confirm topology convergence. Thus, rapid
convergence is implemented.
l RSTP provides the following protection functions, as listed in Table 8-4.
Quidway S7700 Smart Routing Switch
Configuration Guide - Ethernet 8 STP/RSTP Configuration
Issue 01 (2011-07-15) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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