################### Connection tracking ################### Modules ------- .. code-block:: none conntrack { modules { ftp h323 nfs pptp sip sqlnet tftp } } Enables ``conntrack`` modules. All modules are now disabled by default, while they used to be enabled in previous versions. Enabling the modules ensures backwards compatibility — keeping the previous behavior. In most cases they can be disabled by removing the block of configuration. .. code-block:: none delete system conntrack modules For some scenarios it is in fact recommended, like in this example: :ref:`example-high-availability`.