The sysctl control module

This is a module to manage the sysctl attributes. As this module can change some of the kernel behaviours, let's make sure we keep it safe. We are going to do a configuration to make the Linux server act as a gateway. We will not be covering "IPtables" rules in depth in this section. We are going to use a generic sample configuration and try to apply it via the sysctl module.

The playbook to run the module should contain the following:

    - name: enable IP forwarding on IP version 4
      sysctl:
         name: net.ipv4.ip_forward
         value: 1
        sysctrl_set: yes
        state: present
       reload: yes 

A reload option is needed when the task is required to run sysctl -p after the change has been made. This task, with the right firewall rules set, will enable this host to route a packet from one network interface to the other.