With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cswitchUsageByIngrsIntfOctets
cswitch Usage By Ingrs Intf Octets
1.3.6.1.4.1.9.9.201.1.1.1.1.3
The number of ingress octets of a interface which use the switch resource.
Back to CISCO-SWITCH-USAGE-MIB MIB page.
IPHost Network monitor allows you to monitor cswitchUsageByIngrsIntfOctets 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.