With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cefPrefixBytes
CISCO Express Forwarding Prefix Bytes
1.3.6.1.4.1.9.9.492.1.1.2.1.7
If CEF accounting is set to enable per prefix accounting (value of cefCfgAccountingMap object in the cefCfgEntry is set to enable 'perPrefix' accounting), then this object represents the number of bytes switched to this prefix.
Back to CISCO-CEF-MIB MIB page.
IPHost Network monitor allows you to monitor cefPrefixBytes 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.