With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
rcvFramesDiscIllegalLen
rcv Frames Disc Illegal Len
1.3.6.1.4.1.351.110.5.1.1.2.1.1.1.9
The number of frames discarded on the ingress due to illegal length.
Back to CISCO-WAN-FR-PORT-MIB MIB page.
IPHost Network monitor allows you to monitor rcvFramesDiscIllegalLen on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.