github.com/ncdc/docker@v0.10.1-0.20160129113957-6c6729ef5b74/docs/reference/commandline/network_create.md (about) 1 <!--[metadata]> 2 +++ 3 title = "network create" 4 description = "The network create command description and usage" 5 keywords = ["network, create"] 6 [menu.main] 7 parent = "smn_cli" 8 +++ 9 <![end-metadata]--> 10 11 # network create 12 13 Usage: docker network create [OPTIONS] NETWORK-NAME 14 15 Creates a new network with a name specified by the user 16 17 --aux-address=map[] Auxiliary ipv4 or ipv6 addresses used by network driver 18 -d --driver=DRIVER Driver to manage the Network bridge or overlay. The default is bridge. 19 --gateway=[] ipv4 or ipv6 Gateway for the master subnet 20 --help Print usage 21 --internal Restricts external access to the network 22 --ip-range=[] Allocate container ip from a sub-range 23 --ipam-driver=default IP Address Management Driver 24 --ipam-opt=map[] Set custom IPAM driver specific options 25 -o --opt=map[] Set custom driver specific options 26 --subnet=[] Subnet in CIDR format that represents a network segment 27 28 Creates a new network. The `DRIVER` accepts `bridge` or `overlay` which are the 29 built-in network drivers. If you have installed a third party or your own custom 30 network driver you can specify that `DRIVER` here also. If you don't specify the 31 `--driver` option, the command automatically creates a `bridge` network for you. 32 When you install Docker Engine it creates a `bridge` network automatically. This 33 network corresponds to the `docker0` bridge that Engine has traditionally relied 34 on. When launch a new container with `docker run` it automatically connects to 35 this bridge network. You cannot remove this default bridge network but you can 36 create new ones using the `network create` command. 37 38 ```bash 39 $ docker network create -d bridge my-bridge-network 40 ``` 41 42 Bridge networks are isolated networks on a single Engine installation. If you 43 want to create a network that spans multiple Docker hosts each running an 44 Engine, you must create an `overlay` network. Unlike `bridge` networks overlay 45 networks require some pre-existing conditions before you can create one. These 46 conditions are: 47 48 * Access to a key-value store. Engine supports Consul, Etcd, and ZooKeeper (Distributed store) key-value stores. 49 * A cluster of hosts with connectivity to the key-value store. 50 * A properly configured Engine `daemon` on each host in the cluster. 51 52 The `docker daemon` options that support the `overlay` network are: 53 54 * `--cluster-store` 55 * `--cluster-store-opt` 56 * `--cluster-advertise` 57 58 To read more about these options and how to configure them, see ["*Get started 59 with multi-host network*"](../../userguide/networking/get-started-overlay.md). 60 61 It is also a good idea, though not required, that you install Docker Swarm on to 62 manage the cluster that makes up your network. Swarm provides sophisticated 63 discovery and server management that can assist your implementation. 64 65 Once you have prepared the `overlay` network prerequisites you simply choose a 66 Docker host in the cluster and issue the following to create the network: 67 68 ```bash 69 $ docker network create -d overlay my-multihost-network 70 ``` 71 72 Network names must be unique. The Docker daemon attempts to identify naming 73 conflicts but this is not guaranteed. It is the user's responsibility to avoid 74 name conflicts. 75 76 ## Connect containers 77 78 When you start a container use the `--net` flag to connect it to a network. 79 This adds the `busybox` container to the `mynet` network. 80 81 ```bash 82 $ docker run -itd --net=mynet busybox 83 ``` 84 85 If you want to add a container to a network after the container is already 86 running use the `docker network connect` subcommand. 87 88 You can connect multiple containers to the same network. Once connected, the 89 containers can communicate using only another container's IP address or name. 90 For `overlay` networks or custom plugins that support multi-host connectivity, 91 containers connected to the same multi-host network but launched from different 92 Engines can also communicate in this way. 93 94 You can disconnect a container from a network using the `docker network 95 disconnect` command. 96 97 ## Specifying advanced options 98 99 When you create a network, Engine creates a non-overlapping subnetwork for the network by default. This subnetwork is not a subdivision of an existing network. It is purely for ip-addressing purposes. You can override this default and specify subnetwork values directly using the the `--subnet` option. On a `bridge` network you can only create a single subnet: 100 101 ```bash 102 docker network create -d --subnet=192.168.0.0/16 103 ``` 104 Additionally, you also specify the `--gateway` `--ip-range` and `--aux-address` options. 105 106 ```bash 107 network create --driver=bridge --subnet=172.28.0.0/16 --ip-range=172.28.5.0/24 --gateway=172.28.5.254 br0 108 ``` 109 110 If you omit the `--gateway` flag the Engine selects one for you from inside a 111 preferred pool. For `overlay` networks and for network driver plugins that 112 support it you can create multiple subnetworks. 113 114 ```bash 115 docker network create -d overlay 116 --subnet=192.168.0.0/16 --subnet=192.170.0.0/16 117 --gateway=192.168.0.100 --gateway=192.170.0.100 118 --ip-range=192.168.1.0/24 119 --aux-address a=192.168.1.5 --aux-address b=192.168.1.6 120 --aux-address a=192.170.1.5 --aux-address b=192.170.1.6 121 my-multihost-network 122 ``` 123 Be sure that your subnetworks do not overlap. If they do, the network create fails and Engine returns an error. 124 125 # Bridge driver options 126 127 When creating a custom network, the default network driver (i.e. `bridge`) has additional options that can be passed. 128 The following are those options and the equivalent docker daemon flags used for docker0 bridge: 129 130 | Option | Equivalent | Description | 131 |--------------------------------------------------|-------------|-------------------------------------------------------| 132 | `com.docker.network.bridge.name` | - | bridge name to be used when creating the Linux bridge | 133 | `com.docker.network.bridge.enable_ip_masquerade` | `--ip-masq` | Enable IP masquerading | 134 | `com.docker.network.bridge.enable_icc` | `--icc` | Enable or Disable Inter Container Connectivity | 135 | `com.docker.network.bridge.host_binding_ipv4` | `--ip` | Default IP when binding container ports | 136 | `com.docker.network.mtu` | `--mtu` | Set the containers network MTU | 137 | `com.docker.network.enable_ipv6` | `--ipv6` | Enable IPv6 networking | 138 139 For example, let's use `-o` or `--opt` options to specify an IP address binding when publishing ports: 140 141 ```bash 142 docker network create -o "com.docker.network.bridge.host_binding_ipv4"="172.19.0.1" simple-network 143 ``` 144 145 ### Network internal mode 146 147 By default, when you connect a container to an `overlay` network, Docker also connects a bridge network to it to provide external connectivity. 148 If you want to create an externally isolated `overlay` network, you can specify the `--internal` option. 149 150 ## Related information 151 152 * [network inspect](network_inspect.md) 153 * [network connect](network_connect.md) 154 * [network disconnect](network_disconnect.md) 155 * [network ls](network_ls.md) 156 * [network rm](network_rm.md) 157 * [Understand Docker container networks](../../userguide/networking/dockernetworks.md)