Usage: docker network create [OPTIONS] NETWORK Create a network Options: --attachable Enable manual container attachment --ingress Specify the network provides the routing-mesh --aux-address value Auxiliary IPv4 or IPv6 addresses used by Network driver (default map[]) -d, --driver string Driver to manage the Network (default "bridge") --gateway value IPv4 or IPv6 Gateway for the master subnet (default []) --help Print usage --internal Restrict external access to the network --ip-range value Allocate container ip from a sub-range (default []) --ipam-driver string IP Address Management Driver (default "default") --ipam-opt value Set IPAM driver specific options (default map[]) --ipv6 Enable IPv6 networking --label value Set metadata on a network (default []) -o, --opt value Set driver specific options (default map[]) --subnet value Subnet in CIDR format that represents a network segment (default []) --scope value Promote a network to swarm scope (value = [ local | swarm ]) --config-only Creates a configuration only network --config-from The name of the network from which copying the configuration
Creates a new network. The DRIVER accepts bridge or overlay which are the built-in network drivers. If you have installed a third party or your own custom network driver you can specify that DRIVER here also. If you don't specify the --driver option, the command automatically creates a bridge network for you. When you install Docker Engine it creates a bridge network automatically. This network corresponds to the docker0 bridge that Engine has traditionally relied on. When you launch a new container with docker run it automatically connects to this bridge network. You cannot remove this default bridge network, but you can create new ones using the network create command.
$ docker network create -d bridge my-bridge-network
Bridge networks are isolated networks on a single Engine installation. If you want to create a network that spans multiple Docker hosts each running an Engine, you must create an overlay network. Unlike bridge networks, overlay networks require some pre-existing conditions before you can create one. These conditions are:
daemon on each host in the cluster.The dockerd options that support the overlay network are:
--cluster-store--cluster-store-opt--cluster-advertiseTo read more about these options and how to configure them, see “Get started with multi-host network”.
While not required, it is a good idea to install Docker Swarm to manage the cluster that makes up your network. Swarm provides sophisticated discovery and server management tools that can assist your implementation.
Once you have prepared the overlay network prerequisites you simply choose a Docker host in the cluster and issue the following to create the network:
$ docker network create -d overlay my-multihost-network
Network names must be unique. The Docker daemon attempts to identify naming conflicts but this is not guaranteed. It is the user's responsibility to avoid name conflicts.
You should create overlay networks with /24 blocks (the default), which limits you to 256 IP addresses, when you create networks using the default VIP-based endpoint-mode. This recommendation addresses limitations with swarm mode. If you need more than 256 IP addresses, do not increase the IP block size. You can either use dnsrr endpoint mode with an external load balancer, or use multiple smaller overlay networks. See Configure service discovery for more information about different endpoint modes.
When you start a container, use the --network flag to connect it to a network. This example adds the busybox container to the mynet network:
$ docker run -itd --network=mynet busybox
If you want to add a container to a network after the container is already running, use the docker network connect subcommand.
You can connect multiple containers to the same network. Once connected, the containers can communicate using only another container's IP address or name. For overlay networks or custom plugins that support multi-host connectivity, containers connected to the same multi-host network but launched from different Engines can also communicate in this way.
You can disconnect a container from a network using the docker network disconnect command.
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 --subnet option. On a bridge network you can only create a single subnet:
$ docker network create --driver=bridge --subnet=192.168.0.0/16 br0
Additionally, you also specify the --gateway --ip-range and --aux-address options.
$ docker network create \ --driver=bridge \ --subnet=172.28.0.0/16 \ --ip-range=172.28.5.0/24 \ --gateway=172.28.5.254 \ br0
If you omit the --gateway flag the Engine selects one for you from inside a preferred pool. For overlay networks and for network driver plugins that support it you can create multiple subnetworks. This example uses two /25 subnet mask to adhere to the current guidance of not having more than 256 IPs in a single overlay network. Each of the subnetworks has 126 usable addresses.
$ docker network create -d overlay \ --subnet=192.168.1.0/25 \ --subnet=192.170.2.0/25 \ --gateway=192.168.1.100 \ --gateway=192.170.2.100 \ --aux-address="my-router=192.168.1.5" --aux-address="my-switch=192.168.1.6" \ --aux-address="my-printer=192.170.1.5" --aux-address="my-nas=192.170.1.6" \ my-multihost-network
Be sure that your subnetworks do not overlap. If they do, the network create fails and Engine returns an error.
When creating a custom network, the default network driver (i.e. bridge) has additional options that can be passed. The following are those options and the equivalent docker daemon flags used for docker0 bridge:
| Option | Equivalent | Description |
|---|---|---|
com.docker.network.bridge.name | - | bridge name to be used when creating the Linux bridge |
com.docker.network.bridge.enable_ip_masquerade | --ip-masq | Enable IP masquerading |
com.docker.network.bridge.enable_icc | --icc | Enable or Disable Inter Container Connectivity |
com.docker.network.bridge.host_binding_ipv4 | --ip | Default IP when binding container ports |
com.docker.network.driver.mtu | --mtu | Set the containers network MTU |
The following arguments can be passed to docker network create for any network driver, again with their approximate equivalents to docker daemon.
| Argument | Equivalent | Description |
|---|---|---|
--gateway | - | IPv4 or IPv6 Gateway for the master subnet |
--ip-range | --fixed-cidr | Allocate IPs from a range |
--internal | - | Restrict external access to the network |
--ipv6 | --ipv6 | Enable IPv6 networking |
--subnet | --bip | Subnet for network |
For example, let's use -o or --opt options to specify an IP address binding when publishing ports:
$ docker network create \ -o "com.docker.network.bridge.host_binding_ipv4"="172.19.0.1" \ simple-network
By default, when you connect a container to an overlay network, Docker also connects a bridge network to it to provide external connectivity. If you want to create an externally isolated overlay network, you can specify the --internal option.
You can create the network which will be used to provide the routing-mesh in the swarm cluster. You do so by specifying --ingress when creating the network. Only one ingress network can be created at the time. The network can be removed only if no services depend on it. Any option available when creating an overlay network is also available when creating the ingress network, besides the --attachable option.
$ docker network create -d overlay \ --subnet=10.11.0.0/16 \ --ingress \ --opt com.docker.network.driver.mtu=9216 \ --opt encrypted=true \ my-ingress-network