the difference between system priority and bridge ID?

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Jun 18th, 2010
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I am reading the CCNP self Study BCMSN Official Exam Certificate Guide Fourth Edition. There is a System priority in the LACP set up. That is 2 bytes for priority value followed by a 6 byte MAC address. I am wondering what is the difference between system priority and the bridge ID related to STP. Bridge ID also consists of 2 bytes bridge priority and 6 bytes MAC address. if they are the same, why they are given two different names? Could any one give me a help on this?



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Viral Bhutta Tue, 06/22/2010 - 18:13
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LACP system Priority is the combination of the LACP system priority value and the MAC address of the switch.

You can configure it using lacp system-priority priority_value

LACP uses the system priority with the switch MAC address to form the system ID and also during negotiation with other systems.

Each VLAN on each network device has a unique 64-bit bridge ID consisting of a bridge priority value, an extended system ID, and an STP MAC address allocation.

Configuring Bridge ID Priority

spanning-tree vlan vlan_id priority bridge_priority

In short, both values are different.Both are used for different purpose.

Hope this helps.


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