Mstp Concepts - TP-Link Jetstream T1500G-8T User Manual

Configuring Spanning Tree
downstream switch. The value of the accumulated root path cost increases as the BPDU
spreads further.
BPDU
BPDU is a kind of packet that is used to generate and maintain the spanning tree. The
BPDUs (Bridge Protocol Data Unit) contain a lot of information, like bridge ID, root path cost,
port priority and so on. Switches share these information to help determine the spanning
tree topology.

1.2.2 MSTP Concepts

MSTP, compatible with STP and RSTP, has the same basic elements used in STP and RSTP.
Based on the networking topology, this section will introduce some concepts only used in
MSTP.
Figure 1-3 MSTP Topology
MST Region
An MST region consists of multiple interconnected switches. The switches with the same
following characteristics are considered as in the same region:
■ Same region name
■ Same revision level
■ Same VLAN-Instance mapping
Downloaded from ManualsNet.com
region 2
search engine
region 1
region 3
region 4
Spanning Tree
CST
IST
Blocked Port
User Guide 302