Application of MSTP

MSTP

The concept of MSTP is introduced:

MSTP (Multiple Spanning Tree Protocol, multiple spanning Tree Protocol) prunes the loop network into a non-loop tree network, avoids the proliferation and infinite circulation of packets in the loop network, and provides multiple redundant paths for data forwarding to achieve load balancing of VLAN data in the process of data forwarding. MSTP is compatible with STP and RSTP and can make up for the shortcomings of STP and RSTP. It can not only converge quickly, but also make the traffic of different VLAN distribute along their own paths, thus providing a better load sharing mechanism for redundant links.

Characteristics of 2.MSTP:

MSTP sets up the VLAN mapping table (that is, the corresponding table of VLAN and spanning tree) to associate VLAN with spanning tree, and bundles multiple VLAN into one instance by adding the concept of "instance" (integrating multiple VLAN into a set) to save communication overhead and resource utilization.

A.MSTP divides a switching network into multiple domains, and multiple spanning trees are formed in each domain, which are independent of each other.

B.MSTP prunes the loop network into a loop-free tree network, and realizes the load sharing of VLAN data in the process of data forwarding.

C. MSTP is compatible with STP and RSTP

3.H3C configuration MSTP

(1) basic configuration

-region configuration

[H3C] stp region-configuration

-configure domain name

[H3C-mst-redion] region-name name

-configuration revision level

[H3C-mst-region] revison-level level

-configure VLAN and instance mapping

[H3C-mst-region] instance instance-id vlan vlan-list

-activate zone configuration

[H3C-mst-region] active region-configuration

(2) Advanced configuration

-configure the switch as the preferred root bridge

[H3C] stp instance instance-id root primary

-configure the switch to back up the root bridge

[H3C] stp instance instance-id root secondary

(3) compatibility configuration

-configure the port to identify / send MSTP message format

[H3C-GigabitEthernet1/0/1] stp compliance {auto | dot1s | legacy}

-enable summary listening globally

[H3C] stp global config-digest-snooping

-Port open summary listening

[H3C-Ethernet1/0/1] stp config-digest-snooping

Downstream devices configure NO Agreement Check featur

[SWB-Ethernet1/0/1] stp no-agreement-check

(4) MSTP configuration case

All switches are running MSTP, and all switches are configured with two MST instances in the same area: MST1 corresponds to VLAN2 MST12 and corresponds to VLAN3.

Configure in SWA

[SWA] stp region-configuration

[SWA-mst-region] region-name-H3C

[SWA-mst-region] revision-level 0

[SWA-mst-region] instance 1 vlan 2

[SWA-mst-region] instance 2 vlan 3

[SWA-mst-region] active region-configuration

[SWA-mst-region] quuit

[SWA] stp global enable

SWB, SWC, and SWD configurations are the same as SWA