Network - Brocade 4424 or 5424 Fibre switch may experience unexplained reboot

Issue:

Brocade 4424 or 5424 Fibre switch may experience unexplained reboot.

Reboot event will look similar to this, with no events leading to the reboot:

[HAM-1004], 862751, CHASSIS, INFO, M5424, Processor rebooted - Reset.

Solution:

Verify there is nothing attached to the serial port.  Remove any cables connected to the serial port.

Additional Information:

When a Brocade 5424 switch shows it rebooted, without clear explanation or core file created, verify that there is nothing attached to the serial port.  In this switch, there is not a physical Ethernet port for management.  The port on the switch is actually for a serial cable connection.  This port has caused some confusion and network cables have been attached, which can cause unnecessary interrupts.

If you run into this scenario, confirm that there is not an Ethernet cable attached to the serial port.  If so, remove this. 

Another way to check this is that in the supportshow log file the interrupts for serial port will have a fairly high value.  Perform a search in the log for /proc/interrupts:  Gather new after a few hours and compare if this value is increasing rapidly.

/proc/interrupts :

CPU0

1: 370855 UIC0 Level serial