Stp Configuration - Zte ZXR10 2900E series Configuration Manual

ZXR10 2900E Series Configuration Guide
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5.10 STP Configuration

STP Overview
The Spanning Tree Protocol (STP) is applicable to the network with data loops. It uses
certain algorithms to block some redundant links, thus preventing possible network loops.
The Rapid Spanning Tree Protocol (RSTP) is developed on the basis of common STP,
and provides a faster spanning tree convergence by using a mechanism in which the port
state can be rapidly changed from Blocking to Forwarding.
The Multiple Spanning Tree Protocol (MSTP) is developed on the basis of RSTP and STP. It
introduces domains and instances, and recognizes VLAN ID. The whole network topology
structure can be planned into a Common and Internal Spanning Tree (CIST), which is
divided into Common Spanning Tree (CST) and Internal Spanning Tree (IST).
Many devices enabling MSTP construct Multiple Spanning Tree (MST) areas in the
switching network.
considered to exist in an MST area. A switching network can cover many MST areas.
Users can divide the switches into an MST area by using MSTP commands.
l
Same area name.
l
Same reversion level.
l
Same mapping relationship between a VLAN and an instance.
l
Switches should be connected directly.
Multiple spanning trees can be configured in each MSTP area, and they are independent
from each other. Each spanning tree is an Internal Spanning Tree (IST), and it can be
called as Multiple Spanning Tree Instance (MSTI). Common Spanning Tree connects all
MST areas in the switching network. An MST area can be considered as a switch, a CST
is a spanning tree which is generated by STP and RSTP protocol calculation. All ISTs
and CSTs are called as Common and Internal Spanning Tree (CIST). A CIST is a single
spanning tree used to connect all switches.
In this MSTP topology structure, an IST can serve as a single bridge (switch). In this
way, a CTS can serve as an RSTP for the interaction of configuration information (BPDU).
Multiple instances can be created in an IST area and these instances are valid only in this
area. An instance is equivalent to an RSTP, except that the instance needs to perform
BPDU interaction with bridges outside this area.
For the MSTP topological structure, see
SJ-20130731155059-002|2013-11-27 (R1.0)
preview 225.1.1.1
When the devices satisfy the following conditions, they can be
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Figure 5-8.
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