The total number of packets (including bad packets) received that were 64 octets in length (excluding framing bits but including FCS octets). This object is a 64-bit version of etherStatsPkts64Octets. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.
Sources for this description
D-Link official switch MIBsD-Link MIB copies (LibreNMS/Observium Community)