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REE
A
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ONFIGURATION
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Figure 3-70. Configuring Spanning Tree per Port
CLI – This example sets STA attributes for port 7.
Configuring Multiple Spanning Trees
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 Internal Spanning Tree (MST
Instance 0) that connects all bridges and LANs within the MST region.
This switch supports up to 65 instances. You should try to group VLANs
which cover the same general area of your network. However, remember
that you must configure all bridges within the same MSTI Region (page
3-133) 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 Common
Spanning Tree.
To use multiple spanning trees:
Console(config)#interface ethernet 1/7 4-156
Console(config-if)#spanning-tree port-priority 0 4-207
Console(config-if)#spanning-tree cost 50 4-206
Console(config-if)#spanning-tree link-type auto 4-210
Console(config-if)#no spanning-tree edge-port 4-208
Console(config-if)#
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