With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cnfTopFlowsSrcAddressMask
cnf Top Flows Src Address Mask
1.3.6.1.4.1.9.9.387.1.7.8.1.4
Number of bits in source address mask.
Back to CISCO-NETFLOW-MIB MIB page.
IPHost Network monitor allows you to monitor cnfTopFlowsSrcAddressMask 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.