Use the show hardware rate-limit command to determine if packets are being dropped because of a rate limit.

switch(config)# show hardware rate-limit module 1 

Units for Config: packets per second
Allowed, Dropped & Total: aggregated since last clear counters

Rate Limiter Class                       Parameters
------------------------------------------------------------
access-list-log                         Config    : 100            
                                        Allowed   : 0                   
                                        Dropped   : 0                   
                                        Total     : 0

Use the show policy-map interface control-plane command to determine if packets are being dropped because of CoPP.

switch# show policy-map interface control-plane
   class-map copp-system-p-class-exception (match-any)
      match exception ip option
      match exception ip icmp unreachable
      match exception ttl-failure
      match exception ipv6 option
      match exception ipv6 icmp unreachable
      match exception mtu-failure
      set cos 1
      police cir 200 pps , bc 32 packets 
      
      module 27 :
        transmitted 0 packets;
        dropped 0 packets;

      module 28 :
        transmitted 0 packets;
        dropped 0 packets;