@@ -206,6 +206,22 @@ If you need to add an HTTP Proxy, set a different directory or partition for the

 Docker runtime files, or make other customizations, read our Systemd article to

 learn how to [customize your Systemd Docker daemon options](/articles/systemd/).

+## Running Docker with a manually-defined network

+

+If you manually configure your network using `systemd-network` with fedora version 22, containers you start with Docker may be unable to access your network.

+Beginning with version 220, the forwarding setting for a given network (`net.ipv4.conf.<interface>.forwarding`) defaults to *off*. This setting prevents IP forwarding. It also conflicts with Docker which enables the `net.ipv4.conf.all.forwarding` setting within a container.

+

+To work around this, edit the `<interface>.network` file in

+`/usr/lib/systemd/network/` on your Docker host  (ex: `/usr/lib/systemd/network/80-container-host0.network`) add the following block:

+

+```

+[Network]

+...

+IPForward=kernel

+...

+```

+

+This configuration allows IP forwarding from the container as expected.

 ## Uninstall