What is the difference between NetFlow and IPFIX for the Network Flow Monitoring?

NetFlow and IPFIX are both technologies used for network flow monitoring and analysis. They provide insights into network traffic patterns, aiding in performance optimization, troubleshooting, and security analysis.


What is NetFlow?

NetFlow is the original flow monitoring solution, originally developed by Cisco in the late 1990s. Several different versions exist, but most deployments are based on either NetFlow v5 or NetFlow v9. While each version has different capabilities, the basic operation remains the same:

First, a router, switch, firewall, or another type of device will capture information on the network “flows” – basically a set of packets that share a common set of characteristics like source and destination address, source, and destination port, and protocol type. After a flow has gone dormant or a predefined amount of time has passed, the device will export the flow records to an entity known as a “flow collector”.

Finally, a “flow analyzer” makes sense of those records, providing insights in the form of visualizations, statistics, and detailed historical and real-time reporting. In practice, collectors and analyzers are often a single entity, often combined into a larger network performance monitoring solution.

NetFlow operates on a stateful basis. When a client machine reaches out to a server, NetFlow will begin capturing and aggregating metadata from the flow. After the session is terminated, NetFlow will export a single complete record to the collector.

Though it’s still commonly used, NetFlow v5 has a number of limitations. The fields exported are fixed, monitoring is supported only in the ingress direction, and modern technologies like IPv6, MPLS, and VXLAN aren’t supported. NetFlow v9, also branded as Flexible NetFlow (FNF), addresses some of these limitations, allowing users to build custom templates and adding support for newer technologies.

Many vendors also have their own proprietary implementations of NetFlow, such as jFlow from Juniper and NetStream from Huawei. Though the configuration may differ somewhat, these implementations often produce flow records that are compatible with NetFlow collectors and analyzers.

Key Features of NetFlow:

~ Flow Data: NetFlow generates flow records that include details such as source and destination IP addresses, ports, timestamps, packet and byte counts, and protocol types.

~ Traffic Monitoring: NetFlow provides visibility into network traffic patterns, allowing administrators to identify top applications, endpoints, and traffic sources.

~Anomaly Detection: By analyzing flow data, NetFlow can detect anomalies such as excessive bandwidth utilization, network congestion, or unusual traffic patterns.

~ Security Analysis: NetFlow can be used to detect and investigate security incidents, such as distributed denial-of-service (DDoS) attacks or unauthorized access attempts.

NetFlow Versions: NetFlow has evolved over time, and different versions have been released. Some notable versions include NetFlow v5, NetFlow v9, and Flexible NetFlow. Each version introduces enhancements and additional capabilities.


What is IPFIX?

An IETF standard that emerged in the early 2000s, Internet Protocol Flow Information Export (IPFIX) is extremely similar to NetFlow. In fact, NetFlow v9 served as the basis for IPFIX. The primary difference between the two is that IPFIX is an open standard, and is supported by many networking vendors apart from Cisco. With the exception of a few additional fields added in IPFIX, the formats are otherwise nearly identical. In fact, IPFIX is sometimes even referred to as “NetFlow v10”.

Owing in part to its similarities to NetFlow, IPFIX enjoys wide support among network monitoring solutions as well as network equipment.

IPFIX (Internet Protocol Flow Information Export) is an open standard protocol developed by the Internet Engineering Task Force (IETF). It is based on the NetFlow Version 9 specification and provides a standardized format for exporting flow records from network devices.

IPFIX builds upon the concepts of NetFlow and expands them to offer more flexibility and interoperability across different vendors and devices. It introduces the concept of templates, allowing for dynamic definition of flow record structure and content. This enables the inclusion of custom fields, support for new protocols, and extensibility.

Key Features of IPFIX:

~ Template-Based Approach: IPFIX uses templates to define the structure and content of flow records, offering flexibility in accommodating different data fields and protocol-specific information.

~ Interoperability: IPFIX is an open standard, ensuring consistent flow monitoring capabilities across different networking vendors and devices.

~ IPv6 Support: IPFIX natively supports IPv6, making it suitable for monitoring and analyzing traffic in IPv6 networks.

~ Enhanced Security: IPFIX includes security features such as Transport Layer Security (TLS) encryption and message integrity checks to protect the confidentiality and integrity of flow data during transmission.

IPFIX is widely supported by various networking equipment vendors, making it a vendor-neutral and widely adopted choice for network flow monitoring.


So, what is the difference between NetFlow and IPFIX?

The simple answer is that NetFlow is a Cisco proprietary protocol introduced around 1996 and IPFIX is its standards body approved brother.

Both protocols serve the same purpose: enabling network engineers and administrators to collect and analyze network level IP traffic flows. Cisco developed NetFlow so that its switches and routers could output this valuable information. Given the dominance of Cisco gear, NetFlow quickly became the de-facto standard for network traffic analysis. However, industry competitors realized that using a proprietary protocol controlled by its chief rival was not a good idea and hence the IETF led an effort to standardize an open protocol for traffic analysis, which is IPFIX.

IPFIX is based on NetFlow version 9 and was originally introduced around 2005 but took some number of years to gain industry adoption. At this point, the two protocols are essentially the same and though the term NetFlow is still more prevalent most implementations (though not all) are compatible with the IPFIX standard.

Here's a table summarizing the differences between NetFlow and IPFIX:

Aspect NetFlow IPFIX
Origin Proprietary technology developed by Cisco Industry-standard protocol based on NetFlow Version 9
Standardization Cisco-specific technology Open standard defined by IETF in RFC 7011
Flexibility Evolved versions with specific features Greater flexibility and interoperability across vendors
Data Format Fixed-size packets Template-based approach for customizable flow record formats
Template Support Not supported Dynamic templates for flexible field inclusion
Vendor Support Primarily Cisco devices Broad support across networking vendors
Extensibility Limited customization Inclusion of custom fields and application-specific data
Protocol Differences Cisco-specific variations Native IPv6 support, enhanced flow record options
Security Features Limited security features Transport Layer Security (TLS) encryption, message integrity

Network Flow Monitoring is the collection, analysis, and monitoring of traffic traversing a given network or network segment. The objectives may vary from troubleshooting connectivity issues to planning future bandwidth allocation. Flow monitoring and packet sampling can even be useful in identifying and remediating security issues.

Flow monitoring gives networking teams a good idea of how a network is operating, providing insights into overall utilization, application usage, potential bottlenecks, anomalies that may signal security threats, and more. There are several different standards and formats used in network flow monitoring, including NetFlow, sFlow, and Internet Protocol Flow Information Export (IPFIX). Each works in a slightly different way, but all are distinct from port mirroring and deep packet inspection in that they do not capture the contents of every packet passing over a port or through a switch. However, flow monitoring does provide more information than SNMP, which is generally limited to broad statistics like overall packet and bandwidth use.

Network Flow Tools Compared

Feature NetFlow v5 NetFlow v9 sFlow IPFIX
Open or Proprietary Proprietary Proprietary Open Open
Sampled or Flow Based Primarily Flow Based; Sampled Mode is available Primarily Flow Based; Sampled Mode is available Sampled Primarily Flow Based; Sampled Mode is available
Information Captured Metadata and statistical information, including bytes transferred, interface counters and so on Metadata and statistical information, including bytes transferred, interface counters and so on Complete Packet Headers, Partial Packet Payloads Metadata and statistical information, including bytes transferred, interface counters and so on
Ingress/Egress Monitoring Ingress Only Ingress and Egress Ingress and Egress Ingress and Egress
IPv6/VLAN/MPLS Support No Yes Yes Yes

Post time: Mar-18-2024