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@@ -8,7 +8,7 @@ Configure Networking
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Docker uses Linux bridge capabilities to provide network connectivity
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Docker uses Linux bridge capabilities to provide network connectivity
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to containers. The ``docker0`` bridge interface is managed by Docker
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to containers. The ``docker0`` bridge interface is managed by Docker
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-itself for this purpose. Thus, when the Docker daemon starts it :
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+for this purpose. When the Docker daemon starts it :
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- creates the ``docker0`` bridge if not present
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- creates the ``docker0`` bridge if not present
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- searches for an IP address range which doesn't overlap with an existing route
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- searches for an IP address range which doesn't overlap with an existing route
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@@ -34,7 +34,7 @@ At runtime, a :ref:`specific kind of virtual
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interface<vethxxxx-device>` is given to each container which is then
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interface<vethxxxx-device>` is given to each container which is then
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bonded to the ``docker0`` bridge. Each container also receives a
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bonded to the ``docker0`` bridge. Each container also receives a
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dedicated IP address from the same range as ``docker0``. The
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dedicated IP address from the same range as ``docker0``. The
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-``docker0`` IP address is then used as the default gateway for the
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+``docker0`` IP address is used as the default gateway for the
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container.
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container.
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.. code-block:: bash
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.. code-block:: bash
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@@ -55,8 +55,8 @@ which is dedicated to the 52f811c5d3d6 container.
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How to use a specific IP address range
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How to use a specific IP address range
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---------------------------------------
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---------------------------------------
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-Docker will try hard to find an IP range which is not used by the
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-host. Even if it works for most cases, it's not bullet-proof and
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+Docker will try hard to find an IP range that is not used by the
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+host. Even though it works for most cases, it's not bullet-proof and
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sometimes you need to have more control over the IP addressing scheme.
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sometimes you need to have more control over the IP addressing scheme.
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For this purpose, Docker allows you to manage the ``docker0`` bridge
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For this purpose, Docker allows you to manage the ``docker0`` bridge
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@@ -118,25 +118,25 @@ In this scenario:
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Container intercommunication
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Container intercommunication
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-------------------------------
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-------------------------------
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-Containers can communicate with each other according to the ``icc``
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-parameter value of the Docker daemon.
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+The value of the Docker daemon's ``icc`` parameter determines whether
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+containers can communicate with each other over the bridge network.
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- The default, ``-icc=true`` allows containers to communicate with each other.
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- The default, ``-icc=true`` allows containers to communicate with each other.
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- ``-icc=false`` means containers are isolated from each other.
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- ``-icc=false`` means containers are isolated from each other.
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-Under the hood, ``iptables`` is used by Docker to either accept or
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+Docker uses ``iptables`` under the hood to either accept or
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drop communication between containers.
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drop communication between containers.
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.. _vethxxxx-device:
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.. _vethxxxx-device:
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-What's about the vethXXXX device?
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+What is the vethXXXX device?
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-----------------------------------
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-----------------------------------
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Well. Things get complicated here.
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Well. Things get complicated here.
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The ``vethXXXX`` interface is the host side of a point-to-point link
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The ``vethXXXX`` interface is the host side of a point-to-point link
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between the host and the corresponding container; the other side of
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between the host and the corresponding container; the other side of
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-the link being materialized by the container's ``eth0``
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+the link is the container's ``eth0``
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interface. This pair (host ``vethXXX`` and container ``eth0``) are
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interface. This pair (host ``vethXXX`` and container ``eth0``) are
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connected like a tube. Everything that comes in one side will come out
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connected like a tube. Everything that comes in one side will come out
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the other side.
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the other side.
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John Gardiner Myers