User Manual

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Users Manual of XGS-6350-24X4C
Both STP and RSTP only can create sole STP topology. All VLAN messages are forwarded through the only
STP. STP converges too slow, so RSTP ensures a rapid and stable network topology through the handshake
mechanism.
MSTP inherits the rapid handshake mechanism of RSTP. At the same time, MST allows different VLAN to be
distributed to different STPs, creating multiple topologies in the network. In networks created by MSTP,
frames of different VLANs can be forwarded through different paths, realizing the load balance of the VLAN
data.
Different from the mechanism that VLAN distributes STP, MSTP allows multiple VLANs to be distributed to
one STP topology, effectively reducing STPs required to support lots of VLANs.
19.2.1.2 MST Domain
In MSTP, the relationship between VLAN and STP is described through the MSTP configuration table. MSTP
configuration table, configuration name and configuration edit number makes up of the MST configuration
identifier.
In the network, interconnected bridges with same MST configuration identifier are considered in the same
MST region. Bridges in the same MST region always have the same VLAN configuration, ensuring VLAN
frames are sent in the MST region.
19.2.1.3 IST, CST, CIST and MSTI
Figure 2.1 shows an MSTP network, including three MST regions and a switch running 802.1D STP.