docker network create
Refer to the options section for an overview of available OPTIONS for this command.
Description
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 enable Swarm mode, and create an overlay network. To read more about overlay networks with Swarm mode, see “use overlay networks”.
Once you have enabled swarm mode, you can create a swarm-scoped overlay network:
$ docker network create --scope=swarm --attachable -d overlay my-multihost-network By default, swarm-scoped networks do not allow manually started containers to be attached. This restriction is added to prevent someone that has access to a non-manager node in the swarm cluster from running a container that is able to access the network stack of a swarm service.
The —attachable option used in the example above disables this restriction, and allows for both swarm services and manually started containers to attach to the oerlay 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.
Overlay network limitations
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.
For example uses of this command, refer to the examples section below.
Options
| Name, shorthand | Default | Description |
| —attachable | Enable manual container attachment | |
| —aux-address | Auxiliary IPv4 or IPv6 addresses used by Network driver | |
| —config-from | The network from which to copy the configuration | |
| —config-only | Create a configuration only network | |
| —driver , -d | bridge | Driver to manage the Network |
| —gateway | IPv4 or IPv6 Gateway for the master subnet | |
| —ingress | Create swarm routing-mesh network | |
| —internal | Restrict external access to the network | |
| —ip-range | Allocate container ip from a sub-range | |
| —ipam-driver | IP Address Management Driver | |
| —ipam-opt | Set IPAM driver specific options | |
| —ipv6 | Enable IPv6 networking | |
| —label | Set metadata on a network | |
| —opt , -o | Set driver specific options | |
| —scope | Control the network’s scope | |
| —subnet | Subnet in CIDR format that represents a network segment |
Examples
Connect containers
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.
Specify advanced options
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=192.168.10.0/25 \ --subnet=192.168.20.0/25 \ --gateway=192.168.10.100 \ --gateway=192.168.20.100 \ --aux-address="my-router=192.168.10.5" --aux-address="my-switch=192.168.10.6" \ --aux-address="my-printer=192.168.20.5" --aux-address="my-nas=192.168.20.6" \ my-multihost-network Be sure that your subnetworks do not overlap. If they do, the network create fails and Engine returns an error.
Bridge driver options
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 |
| com.docker.network.container_iface_prefix | — | Set a custom prefix for container interfaces |
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 Network internal mode (—internal)
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.
Network ingress mode (—ingress)
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 Run services on predefined networks
You can create services on the predefined docker networks bridge and host .
$ docker service create --name my-service \ --network host \ --replicas 2 \ busybox top Swarm networks with local scope drivers
You can create a swarm network with local scope network drivers. You do so by promoting the network scope to swarm during the creation of the network. You will then be able to use this network when creating services.
$ docker network create -d bridge \ --scope swarm \ --attachable \ swarm-network For network drivers which provide connectivity across hosts (ex. macvlan), if node specific configurations are needed in order to plumb the network on each host, you will supply that configuration via a configuration only network. When you create the swarm scoped network, you will then specify the name of the network which contains the configuration.
node1$ docker network create --config-only --subnet 192.168.100.0/24 --gateway 192.168.100.115 mv-config node2$ docker network create --config-only --subnet 192.168.200.0/24 --gateway 192.168.200.202 mv-config node1$ docker network create -d macvlan --scope swarm --config-from mv-config --attachable swarm-network