I have a layer 3 switch( not a cisco catalyst) that is connected to a cisco router through a MPLS VPLS. Basically the PE on MPLS cloud acts like a layer 2 switch with VPLS.
Switch ===>> PE===>>P===>>PE===>>>Router
-The switch has a minimum of 1000 VLANs
-port 1 is the trunk port connected to PE
-sniffed port 1 and shows that ARP request from the router is being broadcasted by the switch to all of its VLANs.
-Switch CPU reaches up to 70 percent
My question is, what are the instances where the Switch will have to broadcast to all of its VLANs?