Allied Telesis SwitchBlade x3100 Series Manual page 405

Multiple Spanning Tree Protocol (MSTP) Introduction
4.5.8.10 Point-to-Point Port
Refer to 4.5.3.14, and is used by MSTP.
In most cases, select AUTO so that the system can determine the port connection.
Note:
4.5.8.11 Transmit Hold Count
Refer to 4.5.3.15, and is used by MSTP processing.
4.5.8.12 Max Hops (Unique for MSTP)
For MSTP, an additional mechanism is added to control the circulation of old information within a spanning tree
instance (CIST and MSTIs). Each BPDU sent for MSTP will contain a "remaining hop count" field. The value is
initially set by the root bridge for the spanning tree instance (i.e., the Regional Root) where the BPDU origi-
nates. The field is then decremented at each bridge that the information passes through. Once the field reaches
zero, the information stops circulating.
The Max Hops parameter allows the user to specify the value that this field will be initialized to should the
bridge for which it is provisioned become the root of a spanning tree instance. By default, the max hops param-
eter is set to the same value as max age.
4.5.8.13 Multiple Spanning Tree Instance ID (Unique for MSTP)
When the user creates a new Spanning Tree instance for a bridge, a number between 1 and 4096 must be spec-
ified to uniquely identify this Multiple Spanning Tree Instance (MSTI) to other bridges connected to this bridge
using LAN segments. The user also provides a name when the spanning tree instance is created which may be
used for all commands on the local bridge which require a spanning tree instance to be identified. When the
name "MAIN" is provided, the Common and Internal Spanning Tree instance (CIST) is utilized by the command
processing. The MSTID for the CIST is zero.
4.5.8.14 MST Configuration Table (Unique for MSTP)
To associate one or more VLANs with a spanning tree instance, the command is used with the name
ADD STP
or MST ID of a spanning tree instance and one or more VLANs (by name or VID). The MST Configuration Table
contains the VLAN to Spanning Tree mapping for a particular Bridge that is running MSTP. By default, all VLANs
defined for a Bridge running MSTP will be mapped to CIST. As additional MSTIs are defined for the Bridge, this
table will be filled in as the user provisions the desired mapping of defined VLANs for the bridge to the new
MSTI.
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Software Reference for SwitchBlade x3100 Series Switches (Layer Two Switching)