Step-by-Step Guide to Choosing and Setting Up an IDS/IPS for Your Network

Feb 10, 2025

Here’s a step-by-step guide to choosing and setting up an IDS/IPS for your network, tailored to your environment:

1. Choosing an IDS/IPS Solution

Open-Source Options (Cost-Effective)

Snort: Highly customizable, real-time traffic analysis, and rule-based alerts.
Best for: Small to medium-sized environments with skilled administrators.
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Suricata: Similar to Snort but supports multi-threading, faster performance, and additional protocol parsing.
Best for: Networks needing faster throughput.
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Zeek (formerly Bro): Focuses on protocol analysis and high-level network activity logging.
Best for: Advanced network monitoring with deeper traffic insights.
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Commercial Options (More Support and Features)

Palo Alto Networks: Offers advanced threat protection with AI-driven analysis and prevention.
Best for: Enterprises requiring full-featured, integrated network security.
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Cisco Firepower: Combines IDS/IPS, firewall, and advanced malware protection in one platform.
Best for: Businesses with existing Cisco infrastructure.
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Trend Micro TippingPoint: Focuses on high-speed, real-time threat blocking.
Best for: High-throughput networks.
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2. Deploying IDS/IPS in Your Network

Placement in the Network

For Network-Based IDS/IPS (NIDS/NIPS):

Between the DMZ and the internal network.
Between the internet gateway and the firewall.

For Host-Based IDS/IPS (HIDS/HIPS):

Install on critical servers, including the vulnerable DMZ server.

Deployment Modes

IDS Mode (Passive):

Monitors and alerts on malicious traffic but does not block it.
Use this initially to observe traffic patterns without risking service interruptions.

IPS Mode (Active):

Blocks malicious traffic in real-time.
Use this once rules are fine-tuned to avoid false positives blocking legitimate traffic.

3. Configuring IDS/IPS Rules

Predefined Rules:

Use rule sets from reputable sources, such as:

Emerging Threats: Updated signatures for Snort and Suricata.
Cisco Talos: Rule updates for Cisco Firepower and Snort.

Include rules for common vulnerabilities:

EternalBlue and SMB exploits.
FTP brute force and buffer overflow attempts.
Unauthorized access attempts to sensitive ports (e.g., 21, 445).

Custom Rules:

Define rules specific to your environment:

Alert if external IPs access sensitive services.
Monitor traffic from untrusted geolocations.
Detect high-volume requests or unusual traffic spikes.

4. Monitoring and Logging

Integrate the IDS/IPS with a SIEM tool to centralize logs, analyze patterns, and generate alerts. Examples:

Splunk: Comprehensive analysis and automation.
ELK Stack (Elasticsearch, Logstash, Kibana): Open-source alternative for centralized monitoring.
IBM QRadar: Enterprise-grade SIEM with threat intelligence.

Set Up Alerts for:

Matches with critical attack signatures.
Repeated failed login attempts.
Abnormal traffic patterns (e.g., large file uploads or downloads).

5. Testing and Fine-Tuning

Conduct penetration tests using tools like Metasploit or Kali Linux to validate the IDS/IPS effectiveness.
Review logs for false positives and refine rules to reduce unnecessary alerts.