Netflow Notes

Netflow’s primary responsibility is to efficiently provide statistics on IP packets flowing through the network.

Key Purposes of Netflow

  • General network traffic for baselines
  • Usage based network billing
  • Network design \ redesign
  • General network security
  • DDOS and DOS prevention
  • Ongoing network monitoring

Key Netflow fields

  • Source & Destination IP
  • Source & Destination Ports
  • Layer 3 protocol type
  • Type of service markings
  • IP logical interface

Netflow Configuration

Two Requirments

  1. Setting up flow captures
  2. Configure how to send data to the newflow collector

Steps to configure netflow

  1. Configure flow capture with IP flow ingress or egress
  2. Set the netflow collector’s ip flow-export destination
  3. Set the version with ip flow-export version
  4. determine the save interface ip flow-export source

Verify Commands

show ip cache flow
show ip flow interface

different netflow versions collect different types of network traffic.