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Mstp features, Mstp basic concepts – H3C Technologies H3C WX5500E Series Access Controllers User Manual

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MSTP features

Developed based on IEEE 802.1s, MSTP overcomes the limitations of STP, RSTP, and PVST. In addition to

supporting rapid network convergence, it also provides a better load sharing mechanism for redundant

links by allowing data flows from different VLANs to be forwarded along separate paths.
MSTP provides the following features:

Divides a switched network into multiple regions, each of which contains multiple spanning trees
that are independent of one another.

Supports mapping VLANs to spanning tree instances by means of a VLAN-to-instance mapping
table. MSTP can reduce communication overheads and resource usage by mapping multiple

VLANs to one instance.

Prunes a looped network into a loop-free tree, which avoids proliferation and endless cycling of
packets. In addition, it supports load balancing of VLAN data by providing multiple redundant

paths for data forwarding.

MSTP basic concepts

Figure 17

shows a switched network that comprises four MST regions, with each MST region comprising

four MSTP devices.

Figure 18

shows the network topology of MST region 3.

Figure 17 Basic concepts in MSTP

MST region 1

MST region 2

MST region 3

MST region 4

VLAN 1

MSTI 1

VLAN 2

MSTI 2

Other VLANs

MSTI 0

VLAN 1

MSTI 1

VLAN 2

MSTI 2

Other VLANs

MSTI 0

VLAN 1

MSTI 1

VLAN 2

MSTI 2

Other VLANs

MSTI 0

VLAN 1

MSTI 1

VLAN 2&3

MSTI 2

Other VLANs

MSTI 0

CST