How to Monitor and Analyze Network Traffic for Threats in 2025

Irfan Alam August 7, 2025 73 views

Introduction

Network traffic analysis is critical for detecting advanced threats like data exfiltration, lateral movement, and zero-day attacks. In this tutorial, we’ll explore how to monitor and analyze network traffic using modern tools and techniques in 2025.

Step 1: Define Monitoring Objectives

Determine:

Which segments of the network to monitor.
Types of threats to detect (malware, DDoS, insider threats).
Compliance requirements for log retention.

Step 2: Deploy Network Traffic Monitoring Tools

Use open-source and commercial solutions:

Zeek (formerly Bro) for deep packet inspection.
Suricata or Snort for intrusion detection.
Wireshark for detailed packet analysis.

Step 3: Enable NetFlow and sFlow Collection

Configure routers and firewalls to export traffic flow data:

ip flow-export destination 192.168.1.100 2055

Step 4: Set Up a SIEM for Log Correlation

Forward network logs to a SIEM for correlation. Example with Filebeat:

output.elasticsearch:
  hosts: ["https://siem-server:9200"]

Step 5: Establish Baselines for Normal Traffic

Use AI-driven analytics to understand typical patterns and detect anomalies.

Step 6: Monitor for Encrypted Traffic Anomalies

Inspect TLS handshakes and certificate details to identify suspicious encrypted sessions.

Step 7: Automate Alerts

Set up automated alerts for unusual patterns, such as large outbound transfers or connections to blacklisted IPs.

Step 8: Integrate Threat Intelligence Feeds

Use STIX/TAXII feeds to block traffic to known malicious domains.

Step 9: Investigate Suspicious Events

Perform deep packet inspection (DPI) for high-risk events and analyze payloads.

Step 10: Report and Remediate

Share findings with incident response teams and implement long-term fixes.

Conclusion

By combining packet inspection, flow analysis, and SIEM integration, you can detect and respond to advanced threats in real time, making your network more resilient in 2025.