What is NetFlow?

NetFlow is a network protocol developed by Cisco that collects and exports metadata about IP traffic flowing through network devices. Understanding what is NetFlow is important because it helps organizations monitor network activity, analyze traffic patterns, detect anomalies, and investigate potential security incidents. Rather than capturing the contents of network packets, NetFlow records information about network communications, making it valuable for network visibility and cybersecurity monitoring.

Why do organizations use NetFlow?

Modern networks generate large volumes of traffic across users, applications, and connected devices. Monitoring every packet can be resource-intensive, so organizations often use flow records to understand network behavior more efficiently.

Organizations use NetFlow to:

• Monitor network traffic
• Detect unusual communication patterns
• Support security investigations
• Analyze bandwidth usage
• Improve network visibility

These capabilities help security and network teams identify operational issues and potential threats.

How does NetFlow work?

Network devices observe traffic passing through their interfaces and group related packets into flows. The device records metadata about each flow and exports the information to a collector for analysis.

A typical workflow includes:

• A network device observes traffic
• Packets are grouped into flows
• Flow records are generated
• Metadata is exported to a collector
• The collector analyzes network activity
• Administrators review the results

This process provides visibility into communication patterns without capturing packet payloads.

What information does NetFlow collect?

Flow records summarize network communications rather than recording the actual content of transmitted data.

These records help administrators understand how devices communicate across the network.

How does NetFlow support cybersecurity?

Network traffic analysis plays an important role in identifying suspicious behavior. Flow records can reveal unusual connections, unexpected communication patterns, or abnormal traffic volumes that warrant further investigation.

Common security use cases include:

• Detecting network anomalies
• Investigating security incidents
• Identifying suspicious communications
• Monitoring lateral movement
• Supporting threat hunting activities

Organizations often combine flow analysis with other security telemetry for a more complete view of network activity.

Investigating network-related security events

Network traffic provides valuable context during incident response, but security teams also need endpoint visibility to understand how affected systems behave during an attack. Organizations often use capabilities such as:

• Reviewing endpoint-related security incidents
• Investigating suspicious device activity
• Examining affected endpoints
• Gathering context during investigations
• Supporting threat response workflows

Hexnode XDR complements network visibility by helping analysts investigate endpoint activity, review incident details, and gather context from managed devices during security investigations.