What is NetFlow? How NetFlow Protocol Works

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NetFlow is used to monitor network activity and provide valuable insight into how applications are performing. You could use NetFlow to detect when users start logging into your network from new locations. Check more about what NetFlow is and its uses.

What Is NetFlow?

NetFlow is a network protocol developed by Cisco Systems Inc., originally designed to collect information about active Internet Protocol (IP) traffic flowing through a router. The NetFlow protocol was later extended to capture other types of network traffic. IT professionals use NetFlow to analyze network traffic and identify potential problems. NetFlow data is collected at each host interface and stored in a database. NetFlow provides detailed information about the source and destination hosts, ports, protocols, application layer, session attributes, byte counts, time stamps, and packet sizes.

The NetFlow records also contain information about the quality of service provided by the network, including bandwidth utilization, jitter, and latency. NetFlow allows you to monitor bandwidth usage at an application level. You could also get information about traffic flow through your network, like HTTP, FTP, DNS, etc.

How Does Netflow Work?

The basic idea behind Netflow is simple. When configuring a Netflow collector, specify the traffic type you want to capture. Once configured, the collector sends a copy of every packet passing through to a central server.

The first thing you should know about Netflow is that it doesn’t care what kind of traffic passes through your network and only cares how many packets and bytes pass through. Therefore, you can use Netflow to monitor any type of traffic. However, there are some things you should keep in mind when using Netflow.

First, Netflow collects data at regular intervals. By default, Netflow captures data every 5 seconds. If you want to change this interval, you have two options:

  • You can manually increase or decrease the interval, and you can also adjust the interval dynamically. For instance, if you notice that traffic increases, you can increase the interval until you see a decline.
  • You can use SNMP to adjust the interval. SNMP is a standard protocol for managing devices connected to networks. Second, Netflow captures IPv4 and IPv6. Because of this, Netflow works with both protocols.

Finally, Netflow does not store any personally identifiable information. All captured data is anonymous.

What Are Some Uses of NetFlow?

There are several ways in which Netflow can be used. Here are some examples:

Network Monitoring

One of the most common uses for Netflow is to monitor your network. Netflow lets you create reports showing which hosts send and receive the most traffic. You can then use this information to make changes to your network configuration. For instance, if you find that one host is consuming too much bandwidth, you might decide to block that host so that others don’t suffer from poor performance due to it.

Traffic Analysis

Netflow can perform traffic analysis. You can view a graph of all traffic flowing through your network. You can determine whether certain protocols and applications are causing problems. If a user is consistently downloading files faster than normal, you could investigate the cause of the issue.

Performance Testing

Another way in which Netflow can help you test your network is by simulating high-volume traffic. To do this, you need to set up a Netflow collector. Then, you simply send a huge amount of traffic through your network. Afterward, you can compare the results against a baseline measurement taken before you start sending traffic. This comparison will tell you if your network is performing well enough to handle the increased load.

Security Auditing

Netflow can provide valuable information when auditing your network for security. For example, Netflow can show you opened ports if someone gained access to your network. In addition, Netflow can give you detailed information about the packet transmitted over the network.

Network Management

Netflow can be used to manage your network. As mentioned earlier, Netflow allows you to collect flow records regularly. These records contain the number of packets sent and received, the total bytes transferred, and other important statistics. Using these records, you can easily track the health of your network. For example, you can use Netflow to identify potential problems before they become serious. Or, you can use Netflow to detect outages caused by equipment failures.

In conclusion, Netflow is one the best tool for network operations. It allows you to view and manage all types of network traffic, and it is very flexible and will enable you to view and control all kinds of network traffic, including IP traffic, VoIP traffic, and VPN traffic. In addition, Netflow is easy to set up and maintain.

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