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Spanning Tree Vlan Priority for the Cat 3550

Howdy,

If the following from CCO is true:

For priority, the range is 0 to 61440 in increments of 4096; the default is 32768. The lower the number, the more likely the switch will be chosen as the root switch.

Valid priority values are 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and 61440. All other values are rejected.

Why does the switch allow me to configure a priority of 0 or any other number that I want to?

Thanks

1 REPLY
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Re: Spanning Tree Vlan Priority for the Cat 3550

I think the right statement is:

When the switch is in PVST+ mode with MAC address reduction enabled, you can enter one of 16 bridge priority values: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, or 61440.

The bridge priority is combined with the system ID extension (that is, the ID of the VLAN) to create the bridge ID priority for the VLAN.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat4000/rel7_2/config/spantree.htm#36367

When MAC address reduction is not enabled, the switch would allow you to configure any priority value.

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