How to use the Configuring Snort IDS agent skill

What the skill makes the agent do

An agent skill is a folder with instructions (a SKILL.md file) and sometimes helper files that an AI agent reads when your request matches the skill's description. This skill covers installing, configuring and tuning Snort 3, a network intrusion detection system that watches traffic for signs of malicious activity.

When the skill applies, the agent can walk you through installing Snort and its packet-capture library (libdaq), writing a Lua configuration file, downloading community or subscriber rulesets, writing custom detection rules, reducing false alarms and sending alerts to a SIEM (a central security log platform).

• Install Snort and DAQ and verify the install with snort -V
• Configure the capture interface and a systemd service for it
• Build snort.lua with network variables, inspectors and alert outputs
• Download the Snort community ruleset and set up PulledPork 3 for updates
• Write custom rules in a local.rules file
• Validate the configuration and analyze PCAP files

What you need before you start

The skill assumes a Linux system and familiarity with packet capture and rule syntax. The source lists these requirements, and you should confirm each one before following the steps.

• Snort 3 and libdaq, installed from source or a package manager
• A Linux system with libpcap and related build dependencies
• A Snort.org account to download Subscriber or Community rulesets
• An Oinkcode for registered rules, if you use them
• PulledPork 3 for rule updates
• Python 3, for the bundled agent.py script
• A network interface on a span port or network tap, in promiscuous mode

How to install the skill

Download the skill ZIP from this page and unzip it into one of two locations. Use ~/.claude/skills/ to make the skill available across your projects, or use .claude/skills/ inside a single project folder to limit it to that project.

If you use the Claude apps instead, upload the ZIP under Settings, then Capabilities, then Skills.

• Personal install: unzip into ~/.claude/skills/
• Project install: unzip into .claude/skills/ in your project folder
• Claude apps: Settings, Capabilities, Skills, then upload the ZIP

How to trigger the skill with natural requests

You do not need a special command. Describe the task in plain language that matches the skill's purpose, such as deploying Snort, writing a rule, or reducing false positives. The skill's description covers deploying at network boundaries, writing custom rules, tuning rulesets and SIEM integration.

Give the agent specifics where you have them: the interface name, your HOME_NET range, the ports you care about and what you want detected. The more context you provide, the more tailored the configuration will be.

• Walk me through installing Snort 3 and libdaq on Ubuntu, then verifying the install.
• Write a Lua config for Snort with HOME_NET 10.10.0.0/16 and JSON alert output.
• Write a custom rule that alerts on outbound connections to port 4444 with /bin/sh in the payload.
• My Snort rules fire too often on SMB traffic. Help me tune them to reduce false positives.
• Show me how to send Snort alerts to my SIEM.

Validate and test your Snort setup

The skill's reference material includes a command to validate a configuration without starting capture. Run it after editing snort.lua or any rules file. You can also analyze a saved PCAP file to confirm that your rules fire on known traffic before you run Snort on live interfaces.

The reference also includes a command that counts loaded rules, which helps confirm your rulesets were read.

• Validate the configuration without capturing traffic
• Analyze a PCAP file to test detection
• Count loaded rules to confirm rulesets were read

Safety notes: scripts and network access

This skill runs scripts and uses the network. The source says the bundled scripts and commands can change network interface settings and system services, so review each command before running it. The example commands disable offloading features on eth1 and enable promiscuous mode, and they create a systemd service that runs at boot.

The skill also downloads files from the network, including the community ruleset and PulledPork 3 from GitHub. Test on a lab network or a PCAP file first. Do not run the configuration unreviewed on production hosts.

The skill itself says it is unsuitable for monitoring encrypted traffic without TLS inspection and should not replace endpoint detection. Treat Snort as one control among several.

• Read every command before running it with sudo
• Test on a lab host or with PCAP files before production
• Confirm the interface name in the examples (eth1) matches your system
• Keep the Oinkcode and any subscriber credentials private