Paessler Netflow Tester 

Paessler Netflow Tester is a free program that simply dumps the data of all Netflow packets that a computer receives from a Cisco router. This can be useful when debugging bandwidth monitoring configurations based on Cisco's Netflow protocol.
snmp cisco packet sniffer packet sniffing cisco router firewall mrtg bandwidth usage ip volume

PRTG - Paessler Router Traffic Grapher 

An easy to use Windows solution for network/bandwidth usage monitoring. The software supports SNMP, packet sniffing and netflow to generate live readings and trend data to optimize the efficiency of routers, servers and other network components.
snmp packet sniffer packet sniffing cisco router firewall mrtg bandwidth usage ip volume prtg traffic

Paessler SNMP Tester 

Test and debug SNMP requests with Paessler SNMP Tester for free. Run simple SNMP requests against a device in your network, testing each single step of the SNMP request as it is logged into a logfile for analysis.
snmp packet sniffer packet sniffing cisco router firewall mrtg bandwidth usage ip volume prtg traffic