Under certain congestion conditions, you may observe incrementing packet drops representing "tail-drops" in the output of the show interface stats brief command.
device# show interface stats brief
Packets Error Discards CRC
Interface rx tx rx tx rx tx rx
========= =============== =============== =============== ===
Po 1 138641 4297936 0 0 0 0 0
Po 2 0 0 0 0 0 0 0
Lo 1 0 0 0 0 0 0 0
Lo 100 0 0 0 0 0 0 0
Eth 0/1 0 0 0 0 0 0 0
Eth 0/2 0 0 0 0 0 0 0
In such conditions, you must first identify the bottleneck, and then take action to mitigate the congestion.