What is NetFlow5?

Netflow technology was first invented by Darren Kerr and Barry bruins of Cisco Company in 1996, and was registered as an American patent in May of the same year with the patent number of 6243667. NetFlow technology is first used for network devices to accelerate data exchange, which can synchronously measure and count IP data streams forwarded at high speed. After years of technical evolution, Netflow's original function of accelerating data exchange has been gradually realized by special ASIC chips in network devices, and the function of measuring and counting IP data streams flowing through network devices has become more mature, and it has become the most important industry standard for IP/MPLS traffic analysis, statistics and billing recognized in the Internet field. Netflow technology can analyze and measure the communication traffic of IP/MPLS network in detail, and provide detailed statistical data of network operation.

During the development of Netflow technology, Cisco has developed five major practical versions, namely:

Netflow V 1 is the first practical version of netflow technology. Ios 1 1. 1,1.2, 1 1.3 and 12.0 are supported, but they are no longer recommended in today's actual network environment.

Netflow V5 adds the support of data stream BGP as information, and it is the main practical application version at present. IOS 1 1. 1CA and 12.0 and their subsequent IOs versions are supported.

Netflow V7, the version of Netflow supported by Cisco Catalyst switch equipment, requires the MLS or CEF processing engine of the switch.

Netflow V8 adds the function of automatic aggregation of Netflow statistics by network devices (* * * supports 1 1 data aggregation mode), which can greatly reduce the bandwidth requirement of data output. IOS 12.0(3)T, 12.0(3)S, 12. 1 and its subsequent IOs versions are supported.

Netflow V9 is a new flexible and extensible netflow data output format, which uses statistical data output based on templates. You can easily add data fields to be output, and support many new functions of Netflow, such as multicast Netflow, MPLS aware Netflow, BGP next hop V9, IPv6 Netflow and so on. IOS 12.0(24)S and 12.3T and their subsequent IOs versions are supported. In 2003, Cisco's Netflow V9 was also determined by IETF as the IPFIX(IP Flow Information Export) standard from five candidate schemes.