@@ -51,7 +51,7 @@ func (config *Config) InstallFlags() {

 	flag.BoolVar(&config.EnableIpForward, []string{"#ip-forward", "-ip-forward"}, true, "Enable net.ipv4.ip_forward")

 	flag.StringVar(&config.BridgeIP, []string{"#bip", "-bip"}, "", "Use this CIDR notation address for the network bridge's IP, not compatible with -b")

 	flag.StringVar(&config.BridgeIface, []string{"b", "-bridge"}, "", "Attach containers to a pre-existing network bridge\nuse 'none' to disable container networking")

-	flag.StringVar(&config.FixedCIDR, []string{"-fixed-cidr"}, "", "IPv4 subnet for fixed IPs (ex: 10.20.0.0/16)\nthis subnet must be nested in bridge subnet (which is defined by -b or --bip)")

+	flag.StringVar(&config.FixedCIDR, []string{"-fixed-cidr"}, "", "IPv4 subnet for fixed IPs (ex: 10.20.0.0/16)\nthis subnet must be nested in the bridge subnet (which is defined by -b or --bip)")

 	flag.BoolVar(&config.InterContainerCommunication, []string{"#icc", "-icc"}, true, "Enable inter-container communication")

 	flag.StringVar(&config.GraphDriver, []string{"s", "-storage-driver"}, "", "Force the Docker runtime to use a specific storage driver")

 	flag.StringVar(&config.ExecDriver, []string{"e", "-exec-driver"}, "native", "Force the Docker runtime to use a specific exec driver")

@@ -49,6 +49,10 @@ unix://[/path/to/socket] to use.

 **-g**=""

   Path to use as the root of the Docker runtime. Default is `/var/lib/docker`.

+

+**--fixed-cidr**=""

+  IPv4 subnet for fixed IPs (ex: 10.20.0.0/16); this subnet must be nested in the bridge subnet (which is defined by \-b or \-\-bip)

+

 **--icc**=*true*|*false*

   Enable inter\-container communication. Default is true.

@@ -54,6 +54,9 @@ server when it starts up, and cannot be changed once it is running:

  *  `--bip=CIDR` — see

     [Customizing docker0](#docker0)

+ *  `--fixed-cidr` — see

+    [Customizing docker0](#docker0)

+

  *  `-H SOCKET...` or `--host=SOCKET...` —

     This might sound like it would affect container networking,

     but it actually faces in the other direction:

@@ -365,17 +368,25 @@ By default, the Docker server creates and configures the host system's

 can pass packets back and forth between other physical or virtual

 network interfaces so that they behave as a single Ethernet network.

-Docker configures `docker0` with an IP address and netmask so the host

-machine can both receive and send packets to containers connected to the

-bridge, and gives it an MTU — the *maximum transmission unit* or largest

-packet length that the interface will allow — of either 1,500 bytes or

-else a more specific value copied from the Docker host's interface that

-supports its default route.  Both are configurable at server startup:

+Docker configures `docker0` with an IP address, netmask and IP

+allocation range. The host machine can both receive and send packets to

+containers connected to the bridge, and gives it an MTU — the *maximum

+transmission unit* or largest packet length that the interface will

+allow — of either 1,500 bytes or else a more specific value copied from

+the Docker host's interface that supports its default route.  These

+options are configurable at server startup:

  *  `--bip=CIDR` — supply a specific IP address and netmask for the

     `docker0` bridge, using standard CIDR notation like

     `192.168.1.5/24`.

+ *  `--fixed-cidr=CIDR` — restrict the IP range from the `docker0` subnet,

+    using the standard CIDR notation like `172.167.1.0/28`. This range must

+    be and IPv4 range for fixed IPs (ex: 10.20.0.0/16) and must be a subset

+    of the bridge IP range (`docker0` or set using `--bridge`). For example

+    with `--fixed-cidr=192.168.1.0/25`, IPs for your containers will be chosen

+    from the first half of `192.168.1.0/24` subnet.

+

  *  `--mtu=BYTES` — override the maximum packet length on `docker0`.

 On Ubuntu you would add these to the `DOCKER_OPTS` setting in

@@ -55,6 +55,7 @@ expect an integer, and they can only be specified once.

                                                    use 'none' to disable container networking

       --bip=""                                   Use this CIDR notation address for the network bridge's IP, not compatible with -b

       --fixed-cidr=""                            IPv4 subnet for fixed IPs (ex: 10.20.0.0/16)

+                                                   this subnet must be nested in the bridge subnet (which is defined by -b or --bip)

       -D, --debug=false                          Enable debug mode

       -d, --daemon=false                         Enable daemon mode

       --dns=[]                                   Force Docker to use specific DNS servers