NetFlow is a network protocol developed by Cisco for the collection and monitoring of network traffic and volume going to and from a Cisco router or switch. It allows to collect the traffic statistics as NetFlow records which are then collected by a NetFlow collector which could be hardware or software that allows the IT administrator to further analyze the traffic.

That Is configure your router to keep track of all flows and then export them to a central server where we analyze our traffic.

Open standard Devices have

Juniper (which has “JFlow”), 3Com/HP, Dell and Netgear (SFlow), Ericsson (RFlow), Huawei (NetStream) and Alcatel-Lucent (which uses CFlow)

ADVANTAGES

1. Monitors network bandwidth & traffic patterns down to the interface level

2. Identifies which users, applications, & protocols are consuming the most bandwidth

3. Highlights the IP addresses of top talkers

4. Analyzes Cisco NetFlow, Juniper J-Flow, IPFIX, sFlow , Huawei NetStream™ & other flow data.

5. Typically deploys in less than an hour .

6. Check CPU load, memory usage, interface status and even the load of an interface.

7. Track the number of packets sent, bytes sent, packet sizes and more

SolarWinds NetFlow Traffic Analyzer (NTA) is an example of a software based NetFlow collector that collects traffic data.

• First, we have to specify the server: with UDP port 2055.
• NetFlow supports multiple versions, so if you want to use a specific version,
• we can configure what interface the router should use to source the updates from:
• tell the router on what interfaces to track the flows:
• TO verify;

Show ip flow export

Flow export v9 is enabled for main cache

Export source and destination details:

VRF ID: Default

Source (1)      192.168.1.254 (FastEthernet0/0)

Destination (1) 192.168.1.1 (2055)