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Modifying stp bridge and port parameters, Management mac address for stackable devices, Mac learning rate control – Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide User Manual

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You can also enable and disable spanning tree on a port-based VLAN and on an individual port basis,
and enable advanced STP features. Refer to

Spanning Tree Protocol

on page 251.

Modifying STP bridge and port parameters

You can modify the following STP Parameters:

• Bridge parameters - forward delay, maximum age, hello time, and priority
• Port parameters - priority and path cost

For configuration details, refer to

Changing STP bridge and port parameters

on page 256.

Management MAC address for stackable devices

In a traditional stack, the management MAC address of the Active Controller is always used as the STP
bridge ID. The Active Controller management MAC address is always used for control protocols for the
following reasons:

• Unlike standalone devices, each stack member has a different range of MAC addresses.
• In a stack, the management MAC address is software generated, and is always the MAC address of

the Active Controller first port. This ensures consistency across the stack during resets, assuming
that the Active Controller is always the same unit.

• This helps avoid the disruption of frequent topology changes in the stack.

For more information about stacking and Brocade stackable devices, refer to the FastIron Ethernet
Switch Stacking Configuration Guide
.

MAC learning rate control

NOTE
The MAC learning rate control feature is not supported on FastIron X Series devices.

You can set a rate limit to control CPU address updating. The range for this rate limit is 200 to 50,000
per second. The MAC learning rate limit applies to each packet processor, which means that for a
system with two packet processors, each processor can send address messages to the CPU at the
established rate limit.

Syntax: [no] cpu-limit addr-msgs msgsRateLimit

NOTE
Actual rates in hardware may have a variance of +200 or -100.

Modifying STP bridge and port parameters

FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide

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