Packet drops can be investigated by viewing counters using theshow interfaces counterscommand.

• RX_ERR/TX_ERR includes all physical layer (layer-2) related drops, such as FCS error, RUNT frames. If there is RX_ERR or TX_ERR, it usually indicates some physical layer link issues.

• RX_DRP include all layer-2, layer-3, ACL related drops in the switch ingress pipeline, drops due to insufficient ingress buffer.

• TX_DRP include mainly the egress buffer related drop due to congestion, including WRED drop.

• RX_OVR/TX_OVR counts the oversized packets.

• Example:

admin@sonic:~$ show interfaces counters
      Iface            RX_OK      RX_RATE    RX_UTIL    RX_ERR    RX_DRP    RX_OVR            TX_OK      TX_RATE    TX_UTIL    TX_ERR    TX_DRP    TX_OVR
-----------  ---------------  -----------  ---------  --------  --------  --------  ---------------  -----------  ---------  --------  --------  --------
  Ethernet0  471,729,839,997  653.87 MB/s     12.77%         0    18,682         0  409,682,385,925  556.84 MB/s     10.88%         0         0         0
  Ethernet4  453,838,006,636  632.97 MB/s     12.36%         0     1,636         0  388,299,875,056  529.34 MB/s     10.34%         0         0         0
  Ethernet8  549,034,764,539  761.15 MB/s     14.87%         0    18,274         0  457,603,227,659  615.20 MB/s     12.02%         0         0         0
 Ethernet12  458,052,204,029  636.84 MB/s     12.44%         0    17,614         0  388,341,776,615  527.37 MB/s     10.30%         0         0         0
 Ethernet16   16,679,692,972   13.83 MB/s      0.27%         0    17,605         0   18,206,586,265   17.51 MB/s      0.34%         0         0         0
 Ethernet20   47,983,339,172   35.89 MB/s      0.70%         0     2,174         0   58,986,354,359   51.83 MB/s      1.01%         0         0         0
 Ethernet24   33,543,533,441   36.59 MB/s      0.71%         0     1,613         0   43,066,0