---
title: About the kernel_parameter Resource
---

# kernel_parameter

Use the `kernel_parameter` InSpec audit resource to test kernel parameters on Linux platforms.

# Syntax

A `kernel_parameter` resource block declares a parameter and then a value to be tested:

    describe kernel_parameter('path.to.parameter') do
      its('value') { should eq 0 }
    end

where

* `'kernel.parameter'` must specify a kernel parameter, such as `'net.ipv4.conf.all.forwarding'`
* `{ should eq 0 }` states the value to be tested

# Matchers

This InSpec audit resource has the following matchers:

## be

<%= partial "/shared/matcher_be" %>

## cmp

<%= partial "/shared/matcher_cmp" %>

## eq

<%= partial "/shared/matcher_eq" %>

## include

<%= partial "/shared/matcher_include" %>

## match

<%= partial "/shared/matcher_match" %>

## value

The `value` matcher tests the value assigned to the named IP address versus the value declared in the test:

    its('value') { should eq 0 }

# Examples

The following examples show how to use this InSpec audit resource.

## Test if global forwarding is enabled for an IPv4 address

    describe kernel_parameter('net.ipv4.conf.all.forwarding') do
      its('value') { should eq 1 }
    end

## Test if global forwarding is disabled for an IPv6 address

    describe kernel_parameter('net.ipv6.conf.all.forwarding') do
      its('value') { should eq 0 }
    end

## Test if an IPv6 address accepts redirects

    describe kernel_parameter('net.ipv6.conf.interface.accept_redirects') do
      its('value') { should eq 'true' }
    end