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    Configuring Multiple Spanning-Tree Protocol

    You can configure the Multiple Spanning-Tree Protocol (MSTP) under the following hierarchy level:

    To configure the Multiple Spanning-Tree Protocol:

    1. Enable RSTP as the version of spanning-tree protocol to be configured:
      [edit]
      user@host@ edit ... protocols mstp 
    2. Configure the interfaces that participate in the MSTP instance.

      1. Enable configuration of the interface:
        [edit ... protocols mstp]
        user@host# edit interface interface-name
      2. Configure the interface priority:
        [edit ... protocols mstp interface interface-name]
        user@host# set priority interface-priority
      3. (Optional) By default, the interface link cost is determined by the link speed. You can configure the interface link cost to control which bridge is the designated bridge and which port is the designated port:
        [edit ... protocols mstp interface interface-name]
        user@host# set cost interface-link-cost
      4. (Optional) Configure the interface as an edge port:
        [edit ... protocols mstp interface interface-name]
        user@host# set edge
    3. Configure the bridge priority
      [edit ... protocols mstp]
      user@host# set bridge-priority bridge-priority

      For more information, see Understanding Bridge Priority for Election of Root Bridge and Designated Bridge.

    4. Configure hello BPDU timers.

      1. Configure the maximum expected arrival time of hello BPDUs:
        [edit ... protocols mstp]
        user@host# set max-age seconds
      2. Configure the time interval at which the root bridge transmits configuration BPDUs:
        [edit ... protocols mstp]
        user@host# set hello-time seconds
    5. (Optional) By default, the bridge port remains in the listening and learning states for 15 seconds before transitioning to the forwarding state. You can specify a delay from 4 through 20 seconds instead:
      [edit ... protocols mstp]
      user@host# set forward-delay seconds
    6. Configure MSTP-specific options.

      1. Configure the MSTP region configuration name:
        [edit ... protocols mstp]
        user@host# set configuration-name configuration-name
      2. Configure the MSTP revision level:
        [edit ... protocols mstp]
        user@host# set revision-levelrevision-level revision-level
      3. Configure the maximum number of hops a BPDU can be forwarded in the MSTP region:
        [edit ... protocols mstp]
        user@host# set max-hops hops
    7. Verify the MSTP configuration:

      [edit]
      bpdu-destination-mac-address provider-bridge-group; # Optional
      interface interface-name {
      priority interface-priority;
      cost interface-link-cost; # Optional.
      mode (p2p | shared);
      edge; # Optional.
      }
      bridge-priority bridge-priority;
      max-age seconds;
      hello-time seconds;
      forward-delay seconds; # Optional.
      configuration-name configuration-name; # MST region configuration name.
      revision-level revision-level; # MST revision number.
      max-hops hops; # MST maximum hops.
      }
      }
      }

    Modified: 2018-03-08