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How to determine if EXOS is software learning FDB entries.

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TitleHow to determine if EXOS is software learning FDB entries.
This article is made to help determine if EXOS is software learning MAC/FDB addresses.  Most of the time when EXOS is SW learning it's because of a protocol that is enabled that turns on SW learning.  When SW learning is enabled the HAL process is responsible for programing entries into hardware.
  • The below command will show if ports are in software learning.  (Look for the "S" flag)
debug hal show platform learning
  • The FDB.MACAdd log will tell you if the FDB was added by SW.  The type of "0x00000021" means SW learning, and type "0x00001021" means HW learning.
Switch# configure log filter DefaultFilter add events FDB.MACAdd

Switch# en log debug-mode 
WARNING: Debug mode should only be enabled when advised by technical support,
or when advanced diagnosis is required.  Performance degradation is possible.
Debug mode now enabled.

Switch# Show log
12/14/2016 12:06:30.70 <Summ:FDB.MACAdd> Slot-1: MAC 03:F7:F1:D4:12:F2 was added on VLAN 999 port 1:12 with type 0x00000021

Additional notes
The below protocols turn on SW learning:
  • MLAG
  • Netlogin
  • Limit-learning



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