With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cseL2HCAssignedProtoPkts
CISCO SWITCH ENGINE L2 HC Assigned Protocol Packets
1.3.6.1.4.1.9.9.97.1.1.2.1.10
Number of packets belonging to an assigned group of network protocols (typically AppleTalk, DecNet and Vines) received by this switching engine from all sources. This value includes L3 switched packets.
Back to CISCO-SWITCH-ENGINE-MIB MIB page.
IPHost Network monitor allows you to monitor cseL2HCAssignedProtoPkts 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.