BCM chip FP limits the speed of unknown multicast packets

The ACL function of the BCM chip can classify some flows, such as rate limiting of unknown packets, etc.

BCM.0> fp init
BCM.0> fp qset clear
BCM.0> fp qset add bcmFieldQualifyStageIngress
BCM_FIELD_QSET_ADD(StageIngress) okay
BCM.0> fp qset add bcmFieldQualifyInPorts
BCM_FIELD_QSET_ADD(InPorts) okay
BCM.0> fp qset add bcmFieldQualifyPacketRes
BCM_FIELD_QSET_ADD(PacketRes) okay
BCM.0> fp group create 0 1
BCM.0> fp entry create 1 1
BCM.0> fp qual 1 packetres res=L3McUnknown   
BCM.0> fp policer create PolId=1 mode=Committed cbs=1000 cir=64 
BCM.0> fp policer attach entry=1 PolId=1   
BCM.0> fp entry install 1
BCM.0> fp show group 1
GID          1: gid=0x1, instance=0 mode=Single, stage=Ingress lookup=Enabled, ActionResId={-1},pbmp=


{0x00000000000000000000000000000000000000000000000003ffffffffffffff}
         qset={InPorts, PacketRes, Stage, StageIngress},
         selcodes[0]=
{
         FPF1=5
         Intraslice=Primary slice.
 {
InPorts->Stage->StageIngress->PacketRes},


         slice_pri= 0                     {slice_number=0, Entry count=256(0x100),pbmp={0x00000000000000000000000000000000000000000000000003ffffffffffffff}},
         group_status={prio_min=0, prio_max=2147483647, entries_total=4096, entries_free=4095,
                       counters_total=4096, counters_free=4096, meters_total=4096, meters_free=4095}
EID 0x00000001: gid=0x1,
         slice=0, slice_idx=0, part =0 prio=0, flags=0x10602, Installed, Enabled
              tcam: color_indep=1, 
 InPorts 
    DATA=0x00000000000000000000000000000000000000000000000003ffffffffffffff
    MASK=0x00000000000000000000000000000000000000000000000003ffffffffffffff
 Stage 
 StageIngress 
 PacketRes 
    Offset0: 205 Width0: 6 
    DATA=0x00000013 
    MASK=0x0000003f 
         policer={ commit_kbits_sec=0x40, commit_kbits_burst=0x3e8, PacketBased=0, mode=0x1, entries=2, Clean}
         statistics=NULL