Contents

Introduction

Prerequisites

Requirements

Components Used

Background Information

Procedure to filter Snort rules

Introduction

This document describes how to filter snort rules based on the Cisco Secure Rule Update (SRU) and Link State Packet (LSP) version of firepower devices managed by the Firepower Management Centre (FMC).

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

- Knowledge of open-source Snort

- Firepower Management Center (FMC)

- Firepower Threat Defense (FTD)

Components Used

The information in this document is based on these software and hardware versions:

- This article is applicable to all Firepower platforms

- Cisco Firepower Threat Defense (FTD) which runs software version 7.0.0

- Firepower Management Center Virtual (FMC) which runs software version 7.0.0

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Background Information

In the context of intrusion detection systems (IDS) and intrusion prevention systems (IPS), "SID" stands for "Signature ID" or "Snort Signature ID."

A Snort Signature ID (SID) is a unique identifier assigned to each rule or signature within its rule set. These rules are used to detect specific patterns or behaviors in network traffic that can indicate malicious activity or security threats. Each rule is associated with a SID to allow for easy reference and management.

For information on open-source Snort, please visit the SNORT website.

Procedure to filter Snort rules

To view the Snort 2 rule SIDs, navigate to FMC Policies > Access Control > Intrusion, thereafter click the SNORT2  option in the top right corner, as shown in the image:

Snort 2

Navigate to  Rules > Rule Update  and select the latest date to filter the SID.

Rule update

Available Sid’s under snort rules

Select a required option under  Rule State  as shown in the image.

Selecting Rule states

To view the Snort 3 rule SIDs, navigate to  FMC Policies > Access Control > Intrusion , thereafter click the SNORT3 option in the top right corner, as shown in the image:

Snort 3

Navigate to  Advanced Filters  and select the latest date to filter the SID as shown in the image.

Snort 3 filters

LSP under advanced filter

LSP version

Pre-set filter for Sid’s

Select a required option under  Rule state  as shown in the image.

Rule action