SBC 1000/2000 4.1.x : Working with Multiple Spanning Trees

This section contains information about configuring the SBC 1000/2000 to operate within multiple spanning trees in a network.

Important Notes:
  • Region Settings
    • The Region Name must be the same on all switches and nodes in the tree.
    • The Revision must be the same on all switches and nodes in the tree.
  • MSTP Instances
    • The MST ID & VLAN associated to a given Instance ID must be configured identically on all MSTP capable devices on the network.


A network topology of bridges typically contains redundant connections to provide alternate paths in case of link failures. Since there is no concept of time-to-live (TTL) in Ethernet frames, this could result in permanent circulation of frames if there are loops in the network. To prevent loops, a spanning tree connecting all the bridges is formed in real time. The standby/redundant ports are put in a discarding (non-forwarding) state. They are enabled when required.

Default Conditions

On initial startup, the all ports are members of the default MSTP instance, which is disabled by default.


A maximum of 32 user defined MSTP instances may be created.


Child Pages

Managing MST Instances
Modifying Region Settings


redundant_ethernet.jpg (image/jpeg)