Runt Frame

An Ethernet frame that is less than the minimum length of 64 bytes with bad FCS (whereas undersize frames < 64 bytes with good FCS). In a half-duplex Ethernet environment, runt frames are almost always caused by collisions. If runt frames occur when collisions are not high or in a full-duplex Ethernet environment, then they are probably the result of under runs or bad software on a network interface card.