Welcome to SolarWinds blog series “Diving Deeper with NetFlow – Tips and Tricks”. This is the first of 6 part series where you can learn new tips by understanding more about NetFlow and find some everyday use cases for effective network monitoring.


Network problems seem to be a never ending condition for administrators who are charged with both maintaining network performance and delivering advanced network services to their organizations. The restraint in IT budgets and increasing pressure to ensure constant uptime, has pushed network engineers to try and manage existing resources and control costs. For engineers, troubleshooting network related problems and solving bandwidth issues can be achieved by taking advantage of existing flow technologies in your routers and switches. By using NetFlow, monitoring your network traffic not only becomes much easier but also provides greater visibility, by collecting and analyzing the flow data in your network.

What is NetFlow?


NetFlow is a network protocol developed by Cisco Systems for collecting IP traffic information, which eventually became the universally accepted standard on traffic monitoring and is supported on most platforms. NetFlow answers the questions of who (users), what (applications) and how network bandwidth is being used.  By understanding NetFlow much deeper, you can probe more into the insights and everyday uses that you haven’t thought about.

Effectively troubleshoot network issues with NetFlow


NetFlow data contains information about the network traffic, which helps network administrators to attend to issues related to application slowness and network performance degradation. Using NetFlow you can:

  • Identify the hosts involved in a network conversation from the source and destination IP addresses, and its path in the network from the Input and Output interface information.
  • Identify which applications and protocols are consuming your network bandwidth by analyzing the Source and Destination Ports and Protocols.
  • Analyze historical data to see when an incident occurred and its contribution to the total network traffic through the packet and octet count.
  • Ensure the right priorities to the right applications using ToS (Type of Service) analysis.


Flow data helps you keep track of interface details and statistics of top talkers and users, which can help determine the origin of an issue when a problem is reported. With Type of Service (ToS) in NetFlow records, you can understand traffic pattern per Class of Service (COS) in your network. With that you can verify Quality of Service (QoS) levels achieved and optimize network bandwidth for your specific requirements. Additionally, NetFlow data helps you to analyze usage patterns over a particular time and find out who or what uses most of the network bandwidth. NetFlow provides support to quickly troubleshoot application and performance related problems in your network.

Maintaining Network Uptime with NetFlow


Network uptime is critical to an organization’s revenue and an understanding of traffic behavior helps you maintain that. Excessive use of network bandwidth by users and applications can be controlled by identifying the top talkers from real-time and historical data. Manually collecting the flow data and analyzing it is a humongous task. By using a NetFlow analyzer, you can capture NetFlow data from different points in your network and convert them into easy-to-interpret information that help with better management of your enterprise network.

To learn more about NetFlow, check out our NetFlow V9 Datagram Knowledge Series.


The ‘Diving Deeper with NetFlow – Tips and Tricks’ webcast is scheduled on 23rd May 2013. Register here and become an expert in understanding and implementing NetFlow in your enterprise networks.