With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
fcmPortClassFDiscards
fcm Port Class F Discards
1.3.6.1.2.1.10.56.1.4.1.25
The number of Class F frames that were discarded upon reception at this port.
Back to FC-MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor fcmPortClassFDiscards on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.