АМАТЕК AN-SGM28P24-400 [110/322] Overview

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8.1 MSTP introduce

switch supports IEEE802.1d, IEEE802.1w, IEEE802.1s standard STP protocol。

8.1.1 overview

MSTP uses RSTP to converge quickly so that multiple VLAN can be aggregated into a

spanning tree instance, and each instance has a spanning tree topology that is independent of the

other spanning tree instances. This architecture provides multiple forwarding paths for data

streams, can load balance, and reduce the number of spanning tree instances that are required to

support a large number of VLAN。

8.1.2 Multiple spanning tree domains

For instances involved in multiple spanning tree (MST) computations, the same MST

configuration information must be configured in a consistent manner。A set of connected switches

that have the same MST configuration form the MST domain。

The MST configuration determines the domain to which each switch belongs. The

configuration includes domain name, revision number, and MST instance and VLAN assignment

mapping; this information generates a unique abstract (Digest) in the MST configuration。The

summaries in the same domain are the same, and they must be the same. You can look at the

information through the show spanning-tree MST config command。

One domain can have one or more members with the same MST configuration; each member

must have the ability to process RSTP BPDU。There are no restrictions on the number of MST

domains in a network, but each domain supports 16 instances at most. You can only assign one

VLAN to one spanning tree instance at a time。

8.1.3 IST, CIST, and CST

The internal spanning tree (IST), the spanning tree running in the MST domain。

In each MST domain, MSTP maintains multiple instances of creation。Instance 0 is a special