github.com/hustcat/docker@v1.3.3-0.20160314103604-901c67a8eeab/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 --ipv6 Enable IPv6 networking 26 -o --opt=map[] Set custom driver specific options 27 --subnet=[] Subnet in CIDR format that represents a network segment 28 29 Creates a new network. The `DRIVER` accepts `bridge` or `overlay` which are the 30 built-in network drivers. If you have installed a third party or your own custom 31 network driver you can specify that `DRIVER` here also. If you don't specify the 32 `--driver` option, the command automatically creates a `bridge` network for you. 33 When you install Docker Engine it creates a `bridge` network automatically. This 34 network corresponds to the `docker0` bridge that Engine has traditionally relied 35 on. When launch a new container with `docker run` it automatically connects to 36 this bridge network. You cannot remove this default bridge network but you can 37 create new ones using the `network create` command. 38 39 ```bash 40 $ docker network create -d bridge my-bridge-network 41 ``` 42 43 Bridge networks are isolated networks on a single Engine installation. If you 44 want to create a network that spans multiple Docker hosts each running an 45 Engine, you must create an `overlay` network. Unlike `bridge` networks overlay 46 networks require some pre-existing conditions before you can create one. These 47 conditions are: 48 49 * Access to a key-value store. Engine supports Consul, Etcd, and ZooKeeper (Distributed store) key-value stores. 50 * A cluster of hosts with connectivity to the key-value store. 51 * A properly configured Engine `daemon` on each host in the cluster. 52 53 The `docker daemon` options that support the `overlay` network are: 54 55 * `--cluster-store` 56 * `--cluster-store-opt` 57 * `--cluster-advertise` 58 59 To read more about these options and how to configure them, see ["*Get started 60 with multi-host network*"](../../userguide/networking/get-started-overlay.md). 61 62 It is also a good idea, though not required, that you install Docker Swarm on to 63 manage the cluster that makes up your network. Swarm provides sophisticated 64 discovery and server management that can assist your implementation. 65 66 Once you have prepared the `overlay` network prerequisites you simply choose a 67 Docker host in the cluster and issue the following to create the network: 68 69 ```bash 70 $ docker network create -d overlay my-multihost-network 71 ``` 72 73 Network names must be unique. The Docker daemon attempts to identify naming 74 conflicts but this is not guaranteed. It is the user's responsibility to avoid 75 name conflicts. 76 77 ## Connect containers 78 79 When you start a container use the `--net` flag to connect it to a network. 80 This adds the `busybox` container to the `mynet` network. 81 82 ```bash 83 $ docker run -itd --net=mynet busybox 84 ``` 85 86 If you want to add a container to a network after the container is already 87 running use the `docker network connect` subcommand. 88 89 You can connect multiple containers to the same network. Once connected, the 90 containers can communicate using only another container's IP address or name. 91 For `overlay` networks or custom plugins that support multi-host connectivity, 92 containers connected to the same multi-host network but launched from different 93 Engines can also communicate in this way. 94 95 You can disconnect a container from a network using the `docker network 96 disconnect` command. 97 98 ## Specifying advanced options 99 100 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: 101 102 ```bash 103 docker network create -d --subnet=192.168.0.0/16 104 ``` 105 Additionally, you also specify the `--gateway` `--ip-range` and `--aux-address` options. 106 107 ```bash 108 network create --driver=bridge --subnet=172.28.0.0/16 --ip-range=172.28.5.0/24 --gateway=172.28.5.254 br0 109 ``` 110 111 If you omit the `--gateway` flag the Engine selects one for you from inside a 112 preferred pool. For `overlay` networks and for network driver plugins that 113 support it you can create multiple subnetworks. 114 115 ```bash 116 docker network create -d overlay 117 --subnet=192.168.0.0/16 --subnet=192.170.0.0/16 118 --gateway=192.168.0.100 --gateway=192.170.0.100 119 --ip-range=192.168.1.0/24 120 --aux-address a=192.168.1.5 --aux-address b=192.168.1.6 121 --aux-address a=192.170.1.5 --aux-address b=192.170.1.6 122 my-multihost-network 123 ``` 124 Be sure that your subnetworks do not overlap. If they do, the network create fails and Engine returns an error. 125 126 # Bridge driver options 127 128 When creating a custom network, the default network driver (i.e. `bridge`) has additional options that can be passed. 129 The following are those options and the equivalent docker daemon flags used for docker0 bridge: 130 131 | Option | Equivalent | Description | 132 |--------------------------------------------------|-------------|-------------------------------------------------------| 133 | `com.docker.network.bridge.name` | - | bridge name to be used when creating the Linux bridge | 134 | `com.docker.network.bridge.enable_ip_masquerade` | `--ip-masq` | Enable IP masquerading | 135 | `com.docker.network.bridge.enable_icc` | `--icc` | Enable or Disable Inter Container Connectivity | 136 | `com.docker.network.bridge.host_binding_ipv4` | `--ip` | Default IP when binding container ports | 137 | `com.docker.network.mtu` | `--mtu` | Set the containers network MTU | 138 139 The following arguments can be passed to `docker network create` for any network driver, again with their approximate 140 equivalents to `docker daemon`. 141 142 | Argument | Equivalent | Description | 143 |--------------|----------------|--------------------------------------------| 144 | `--gateway` | - | ipv4 or ipv6 Gateway for the master subnet | 145 | `--ip-range` | `--fixed-cidr` | Allocate IPs from a range | 146 | `--internal` | - | Restricts external access to the network | 147 | `--ipv6` | `--ipv6` | Enable IPv6 networking | 148 | `--subnet` | `--bip` | Subnet for network | 149 150 For example, let's use `-o` or `--opt` options to specify an IP address binding when publishing ports: 151 152 ```bash 153 docker network create -o "com.docker.network.bridge.host_binding_ipv4"="172.19.0.1" simple-network 154 ``` 155 156 ### Network internal mode 157 158 By default, when you connect a container to an `overlay` network, Docker also connects a bridge network to it to provide external connectivity. 159 If you want to create an externally isolated `overlay` network, you can specify the `--internal` option. 160 161 ## Related information 162 163 * [network inspect](network_inspect.md) 164 * [network connect](network_connect.md) 165 * [network disconnect](network_disconnect.md) 166 * [network ls](network_ls.md) 167 * [network rm](network_rm.md) 168 * [Understand Docker container networks](../../userguide/networking/dockernetworks.md)