How to configure İcx 7750 ports breakout

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Akbar Ali

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Posted 4 months ago

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Michael Brado, Official Rep

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There are different FI version Stacking Guides under the ICX 7750 documents on our Support portal as a good starting point.
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Dacvar, Employee

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Hello Akbar

To be able to configure a switch port for breakout, the switch must be in store-and-forward mode. The default is cut-through mode. 
 To enable store-and-forward mode: 

config t 
wr mem 
To configure breakout on port 1/2/6 for example:

Note: Remove any configuration on the port before issuing 

config t 
breakout ethernet 1/2/6 
wr mem 
Verify your breakout configuration: 

show interface brief 

Note: The new port numbers end with :1 to :4. This indicated which 10G port is broke out of the 40G port. From this point on, all ports will be referenced like 1/2/6:1 for all configuration purposes. 

show breakout 

Your ports are ready to be configured and used. 

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Yamini Elango, Employee

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Configuring 40 Gbps breakout ports

Use the breakout ethernet command to divide available ICX 7750 40 Gbps ports into four 10 Gbps sub-ports when a breakout cable is


By default, all main 40 Gbps ports are configured to come up in 40 Gbps mode. Once ports are cabled for breakout, configure the ports

using the breakout ethernet command at the global configuration level.


You should remove any interface-level configuration before configuring breakout.


If the device is in cut-through mode and you attempt to configure breakout, an error is returned. Cut-through must be disabled

to return the unit to store-and-forward mode before breakout is configured.

The breakout ethernet command first checks for existing configuration on the port. If existing configuration is detected, an error

message similar to the following is displayed to indicate that prior configuration must be removed.

Device# configure terminal

Device(config)# breakout ethernet 1/1/11

Error: Port 1/1/11 is tagged

Once any previous configuration is removed, the breakout ethernet command must be reissued. The resulting configuration must be

saved, and the unit must then be reloaded before the four 10 Gbps sub-ports are created and accessible

For example, to configure ports 1/3/1 through 1/3/6 for breakout, issue the following commands:

Device# configure terminal

Device(config)# breakout ethernet 1/3/1 to ethernet 1/3/6

For more detail, check  Brocade FastIron Management Configuration Guide

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Ryan Guerrero, Employee

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Correct commands

config t 
breakout ethernet 1/2/1 
wr mem