Allied Telesis AT-S95 WEB - Manual (Page 149)

Configuring Spanning Tree
Configuring Multiple Spanning Tree
Page 149
Defining MSTP Instance Settings
MSTP maps VLANs into STP instances. Packets assigned to various VLANs are transmitted along different paths
within Multiple Spanning Tree Regions (MST Regions). Regions are one or more Multiple Spanning Tree bridges
by which frames can be transmitted. In configuring MSTP, the MST region to which the device belongs is defined.
A configuration consists of the name, revision, and VLANs that belong to an instance. To configure devices in the
same region, the three components must be the same for all the devices.
Network Administrators can define MSTP Instances settings using the MSTP Instance Settings Page.
To define MSTP interface settings:
1. Click Layer 2 > MSTP. The MSTP Page opens.
2. Click Configure next to the Configure Instance Settings option. The MSTP Instance Settings Page opens:
Figure 99: MSTP Instance Settings Page
The MSTP Instance Settings Page contains the following fields:
• Instance ID — Defines the VLAN group to which the interface is assigned. The possible field range is 1-15.
• Included VLAN — Maps the selected VLAN to the selected instance. Each VLAN belongs to one instance.
• Bridge Priority — Specifies the selected spanning tree instance device priority. The possible field range is
0-61440 in multiples of 4096.
• Designated Root Bridge ID — Indicates the ID of the bridge with the lowest path cost to the instance ID.
• Root Path Cost — Indicates the selected instance’s path cost.
• Root Port — Indicates the selected instance’s root port.
• Remaining Hops — Indicates the number of hops remaining in the region until the BPDU is discarded.
• Bridge ID — Indicates the bridge ID of the selected instance.