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DCS-3950 series Ethernet switch manual
z CIST port roles: root port, designated port, alternate port and backup port
z On top of those roles, each MSTI port has one new role: master port.
The port roles in the CIST (root port, designated port, alternate port and backup port)
are defined in the same ways as those in the RSTP.
10.1.3 MSTP Load Balance
In a MSTP region, VLANs can be mapped to various instances. That can form various
topologies. Each instance is independent from the others and each distance can has its
own attributes such as bridge priority and port cost etc. Consequently, the VLANs in
different instances have their own paths. The traffic of the VLANs are load-balanced.
10.2 MSTP Configuration
10.2.1 MSTP Configuration Task List
1. Enable the MSTP and set the running mode
2. Configure instance parameters
3. Configure MSTP region parameters
4. Configure MSTP time parameters
5. Configure the fast migrate feature for MSTP
6. Configure the format of port packet
7. Configure the snooping attribute of authentication key
8. Configure the FLUSH mode once topology changes
1. Enable MSTP and set the running mode
Command Notes
Global Mode and Interface Mode
spanning-tree
no spanning-tree
Enable/Disable MSTP
Global Mode
spanning-tree mode {mstp|stp}
no spanning-tree mode
Set MSTP running mode
Interface Mode
spanning-tree mcheck
Force port migration to run under MSTP
2. Configure instance parameters
Command Notes
Global Mode
spanning-tree mst <instance-id>
priority <bridge-priority>
Set bridge priority for specified instance