HPE FlexNetwork 5130 HI SERIES

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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 allows data flows of different VLANs to be
forwarded along separate paths. This provides a better load sharing mechanism for redundant links.
MSTP provides the following features:
• MSTP divides a switched network into multiple regions, each of which contains multiple
spanning trees that are independent of one another.
• MSTP 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.
• MSTP prunes a loop network into a loop-free tree, which avoids proliferation and endless
cycling of packets in a loop network. In addition, it supports load balancing of VLAN data by
providing multiple redundant paths for data forwarding.
• MSTP is compatible with STP and RSTP, and partially compatible with PVST.
MSTP basic concepts
Figure 6 shows a switched network that comprises four MST regions, each MST region comprising
four MSTP devices. Figure 7 sho
ws the networking topology of MST region 3.
Figure 20 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