add short info about conntrack modules (#731)

1 files changed, 33 insertions, 0 deletions

diff --git a/docs/configuration/system/conntrack.rst b/docs/configuration/system/conntrack.rst
new file mode 100644
index 00000000..7f7e4b77
--- /dev/null
+++ b/docs/configuration/system/conntrack.rst
@@ -0,0 +1,33 @@
+###################
+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`.