A:
Among the spanning tree protocols, MSTP is compatible with RSTP and STP, and RSTP is compatible with STP. MSTP has fast convergence. Multiple spanning trees perform load balancing and transmit traffic in different VLANs along different paths. To enable MSTP, perform the following steps:
Step 1: Run the stp mode mstp command in the system view to set the STP working mode to MSTP.
Step 2: Configure and activate an MST region. An example is as follows:
<HUAWEI> system-view
[HUAWEI] stp region-configuration
[HUAWEI-mst-region] region-name RG1 //Configure a region named RG1.
[HUAWEI-mst-region] instance 1 vlan 2 to 10 //Map VLANs 2 through 10 to MSTI 1.
[HUAWEI-mst-region] instance 2 vlan 11 to 20 //Map VLANs 11 through 20 to MSTI 2.
[HUAWEI-mst-region] active region-configuration //Activate the MST region configuration.
[HUAWEI-mst-region] quit
Two switches belong to the same MST region only if they have the same MST region name, MSTI-VLAN mapping, and MST region revision level.
Step 3: Configure the root bridge and secondary root bridge. An example is as follows:
# Configure SwitchA as the root bridge in MSTI 1.
[SwitchA] stp instance 1 root primary
# Configure SwitchB as the secondary root bridge in MSTI 1.
[SwitchB] stp instance 1 root secondary
Step 4: Set the path costs of the ports. An example is as follows:
# Configure SwitchC to use Huawei's proprietary algorithm to calculate the path cost and set the path cost of GE0/0/2 to 20000 in MSTI 2.
[SwitchC] stp pathcost-standard legacy
[SwitchC] interface gigabitethernet 0/0/2
[SwitchC-GigabitEthernet0/0/2] stp instance 2 cost 20000
[SwitchC-GigabitEthernet0/0/2] quit
Step 5: Run the stp enable command in the system view to enable MSTP.
For more information about configurations and principles of MSTP, see the corresponding product documentation.
Step 1: Log in to Huawei enterprise technical support website: http://support.huawei.com/enterprise.
Step 2: Select the product, for example, Switch > S5700.
Step 3: Select the corresponding product documentation from the Downloadable Product Documentation Package.
Step 4: See MSTP Configuration under Configuration > CLI-based Configuration Guide > Ethernet Switching Configuration Guide.
