Now that docker sets /proc/sys/net/ipv4/ip_forward by default, remove
the step to enable it in the installation docs.

Docker-DCO-1.1-Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> (github: jpoimboe)

docs/sources/installation/archlinux.rst

@@ -71,21 +71,3 @@ To start on system boot:
::

    sudo systemctl enable docker
    
Network Configuration
---------------------

IPv4 packet forwarding is disabled by default on Arch, so internet access from inside
the container may not work.

To enable the forwarding, run as root on the host system:

::

    sysctl net.ipv4.ip_forward=1
    
And, to make it persistent across reboots, enable it on the host's **/etc/sysctl.d/docker.conf**:

::

    net.ipv4.ip_forward=1

docs/sources/installation/frugalware.rst

@@ -60,21 +60,3 @@ To start on system boot:
::

    sudo systemctl enable lxc-docker
    
Network Configuration
---------------------

IPv4 packet forwarding is disabled by default on FrugalWare, so Internet access from inside
the container may not work.

To enable packet forwarding, run the following command as the ``root`` user on the host system:

::

    sysctl net.ipv4.ip_forward=1
    
And, to make it persistent across reboots, add the following to a file named **/etc/sysctl.d/docker.conf**:

::

    net.ipv4.ip_forward=1

docs/sources/installation/gentoolinux.rst

@@ -82,19 +82,3 @@ To start on system boot:
.. code-block:: bash

   sudo systemctl enable docker.service

Network Configuration
^^^^^^^^^^^^^^^^^^^^^

IPv4 packet forwarding is disabled by default, so internet access from inside
the container will not work unless ``net.ipv4.ip_forward`` is enabled:

.. code-block:: bash

   sudo sysctl -w net.ipv4.ip_forward=1

Or, to enable it more permanently:

.. code-block:: bash

   echo net.ipv4.ip_forward = 1 | sudo tee /etc/sysctl.d/docker.conf

docs/sources/installation/google.rst

@@ -43,29 +43,22 @@
    $ gcutil ssh docker-playground
    docker-playground:~$ 

5. Enable IP forwarding:

.. code-block:: bash

    docker-playground:~$ echo net.ipv4.ip_forward=1 | sudo tee /etc/sysctl.d/99-docker.conf 
    docker-playground:~$ sudo sysctl --system

6. Install the latest Docker release and configure it to start when the instance boots:
5. Install the latest Docker release and configure it to start when the instance boots:

.. code-block:: bash

    docker-playground:~$ curl get.docker.io | bash
    docker-playground:~$ sudo update-rc.d docker defaults

7. If running in zones: ``us-central1-a``, ``europe-west1-1``, and ``europe-west1-b``, the docker daemon must be started with the ``-mtu`` flag. Without the flag, you may experience intermittent network pauses. 
6. If running in zones: ``us-central1-a``, ``europe-west1-1``, and ``europe-west1-b``, the docker daemon must be started with the ``-mtu`` flag. Without the flag, you may experience intermittent network pauses. 
`See this issue <https://code.google.com/p/google-compute-engine/issues/detail?id=57>`_ for more details.

.. code-block:: bash

    docker-playground:~$ echo 'DOCKER_OPTS="$DOCKER_OPTS -mtu 1460"' | sudo tee -a /etc/default/docker
    docker-playground:~$ sudo service docker restart

8. Start a new container:
7. Start a new container:

.. code-block:: bash