1-10z MSTP supports mapping VLANs to MST instances by means of a VLAN-to-instance mapping table.MSTP introduces “instance” (integrates multiple VLANs into a set) and can bind multiple VLANs toan instance, thus saving communication overhead and improving resource utilization.z MSTP divides a switched network into multiple regions, each containing multiple spanning treesthat are independent of one another.z MSTP prunes a ring network into a network with tree topology, preventing packets from beingduplicated and forwarded in a network endlessly. Furthermore, it offers multiple redundant pathsfor forwarding data, and thus achieves load balancing for forwarding VLAN data.z MSTP is compatible with STP and RSTP.Basic MSTP TerminologiesFigure 1-4 illustrates basic MSTP terms (assuming that MSTP is enabled on every device in this figure).Figure 1-4 Basic MSTP terminologiesMST regionA multiple spanning tree region (MST region) comprises multiple physically-interconnectedMSTP-enabled devices and the corresponding network segments connected to these devices. Thesedevices have the same region name, the same VLAN-to-MSTI mapping configuration and the sameMSTP revision level.A switched network can contain multiple MST regions. You can group multiple devices into one MSTregion by using the corresponding MSTP configuration commands.As shown in Figure 1-4, all the devices in region A0 are of the same MST region-related configuration,including:z Region namez VLAN-to-MSTI mapping (that is, VLAN 1 is mapped to MSTI 1, VLAN 2 is mapped to instance 2,and the other VLANs are mapped to CIST.)z MSTP revision level (not shown in Figure 1-4)
