@Clive_A 

Thanks for you feedback, and responses, but i confirm that the switch SG3428x block the communication between deco M9 AP, if i replace the switch by and unmanged switch it's works and i see the communication between the deco on ethernet, if i put back the switch it's doesn't works (Always on wireless between the deco M9 AP) and the processor on switch is 90% and need to reboot. 

My questions is now, what parameter to change to allow this communication and have the same situation as unmanaged switch ? 

Thanks for your help

Christophe 

  @Sorcier062 

I have tested to reset the switch TL-SG3428x to restart with a new configuration, today the deco pass the switch TL-SG3428x without freeze and storm broadcast. 

I"m waiting 2 or 3 days to confirm if it's the good solution. 

Chris 

  @Sorcier062 

After 3 days to test if the solutiion was ok, i confirm that it's a good solution to reset the switch a start with a new configuration, perharps we have a bad upgrade from the last firmware because now it's ok deco to deco on ethernet is OK.

very unhappy from the support L2 don't propose this solution before... 

Chris