Command Usage; To Use Multiple Spanning Trees; Configuring Spanning Tree Bridge Priorities - AMX NXA-ENET8-2POE Operation/Reference Manual

Configuring the NXA-ENET8-2POE
MSTI Configuration parameters (Cont.)
MSTI Mapping
• MSTI
• VLANs Mapped

Command Usage

MSTP generates a unique spanning tree for each instance. This provides multiple pathways across the
network, thereby balancing the traffic load, preventing wide-scale disruption when a bridge node in a single
instance fails, and allowing for faster convergence of a new topology for the failed instance.
By default all VLANs are assigned to the Common Internal Spanning Tree (CIST, or MST Instance 0) that
connects all bridges and LANs within the MST region. This switch supports up to 7 instances. You should try
to group VLANs which cover the same general area of your network. However, remember that you must
configure all bridges that exist within the same MSTI Region with the same set of instances, and the same
instance (on each bridge) with the same set of VLANs. Also, note that RSTP treats each MSTI region as a
single node, connecting all regions to the CIST.

To Use Multiple Spanning Trees

1.
Set the spanning tree type to MSTP (see the Configuring Global Settings for STA section on page 91).
2.
Add the VLANs that will share this MSTI on the MSTI Mapping page.
3.
Enter the spanning tree priority for the CIST and selected MST instance on the MSTI Priorities page.
All VLANs are automatically added to the CIST (MST Instance 0).
To ensure that the MSTI maintains connectivity across the network, you must configure a related set of bridges
with the same MSTI settings.
1.
Click Configuration, Spanning Tree, MSTI Mapping.
2.
Enter the VLAN group to add to the instance in the VLANs Mapped column. Note that the specified
member does not have to be a configured VLAN.
3.
Click Save.

Configuring Spanning Tree Bridge Priorities

Use the MSTI Priority Configuration page to configure the bridge priority for the CIST and any configured
MSTI. Remember that RSTP looks upon each MST Instance as a single bridge node.
FIG. 71
MSTI Priority Configuration
94
Instance identifier to configure. The CIST is not available for explicit mapping, as it
will receive the VLANs not explicitly mapped. (Range: 1-7)
VLANs to assign to this MST instance. The VLANs must be separated with
comma and/or space. A VLAN can only be mapped to one MSTI. (Range: 1-4094)
NXA-ENET8-2POE Gigabit Ethernet Layer 2 PoE Switch