Managing NetFlow Congestion
NetFlow’s substantial bandwidth consumption can adversely affect the performance of the devices it monitors. This problem is exacerbated when replicating flows to multiple NetFlow consumers (collectors).
Consequently, some organizations opt for sampling IP packets instead, utilizing sFlow as an alternative. While sFlow consumes significantly less bandwidth, it poses the disadvantage of hindering IT teams from identifying critical network security or performance issues.
For individuals with experience managing NetFlow, network performance issues resulting from flow congestion is a recurring challenge. There are three primary methods for managing NetFlow congestion:
1. Reduce the size of NetFlow packets
2. Eliminate NetFlow capture on non-essential devices or interfaces
3. Build additional capacity to accommodate NetFlow traffic.
Reducing the size of NetFlow packets can be achieved by filtering unnecessary traffic. Some devices support built-in filtering, which can eliminate certain types of traffic that might be redundant. This will reduce the amount of traffic that gets swept into the flow cache. NetFlow v9 and newer, where template-based records allow specifying which fields to export, can also be used to reduce the size of the UDP datagram. For instance, eliminating IPv6 fields in a network that exclusively utilizes IPv4. The most prevalent method involves disabling NetFlow capture on non-essential devices or specific interfaces.
Although these methods and practices are effective, their implementation is laborious and susceptible to human error, which ultimately reduces visibility to network-wide issues.
On the other hand, the apprehension of missing a network-wide issue prompts many IT organizations to capture all NetFlow and build capacity to accommodate the increased flow volume. This approach will work, but the cost to do so makes it viable for very few organizations.
If you’re struggling to balance performance, cost, and complete visibility across your network, Tavve’s PacketRanger offers a better path forward. With advanced filtering, intelligent data forwarding, and robust scalability, you can optimize flow data without sacrificing critical insight.
Reach out to Tavve today and schedule a demo.
