Use MAC ACL to isolate the failure point

For L2 traffic, besides checking drops/discard counter, another way to isolate the failure point is to use the MAC ACL, like

mac access-list macCount
   counters per-entry
   10 permit 00:00:03:03:00:14 00:00:00:00:00:00 04:68:03:03:00:14 00:00:00:00:00:00 log
   20 permit any any log
!
interface Ethernet3/1
   switchport access vlan 3003
   mac access-group macCount in

The above MAC acl - macCount is count the number of packets with source MAC - 0000.0303.0014 and dest MAC - 0468.0303.0014. And it is applied on Eth3/1 ingress direction (egress ACL is not supported)

Router#show mac access-lists
MAC Access List macCount
        counters per-entry
        10 permit 00:00:03:03:00:14 00:00:00:00:00:00 04:68:03:03:00:14 00:00:00:00:00:00 log [match 216114288 packets, 0:00:00 ago]
        20 permit any any log

This is an Arista DCS-7280CR2A-60-F with 4.22.0F