I found, use SNMP to get interface traffic counter and show interface traffic, less than actual traffic usage. these may not include ethernet mac header,ethernet Preamble, an Interframe gap, and so on.
for example, I use Spirent test 10G traffic, the result of physical traffic is 10G, show interface xe-0/0/3 , it only shows 9.5G. If I use 128byte packet 10G testing. it shows almost 8.6G on the switch
is there any command and SNMP OID can monitor actual traffic usage include them?