This Counter32 object counts good packets received by a port that are shorter than 64 bytes, excluding framing bits but including the FCS. An admin investigating Ethernet frame errors on a link watches this counter, alongside rxFragments, to spot a device sending malformed short frames. For example, a port with a rising undersize-packet count paired with a misbehaving NIC on the connected device would point the admin toward that device's network driver or hardware as the source of the malformed frames.