With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
rprSpanStatsInUcastClassCFrames
rpr Span Stats In Ucast Class C Frames
1.0.8802.17.1.1.1.3.4.1.9
The number of received (PHY to MAC) classC unicast frames.
Back to IEEE-802DOT17-RPR-MIB MIB page.
IPHost Network monitor allows you to monitor rprSpanStatsInUcastClassCFrames on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.