Provided by: docker.io_24.0.5-0ubuntu1~20.04.1_amd64 
NAME
docker-network-create - Create a network
SYNOPSIS
docker network create [OPTIONS] NETWORK
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" ⟨https://docs.docker.com/network/overlay/⟩.
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
⟨https://github.com/moby/moby/issues/30820⟩. 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
⟨https://docs.docker.com/engine/swarm/networking/#configure-service-discovery⟩ for more
information about different endpoint modes.
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
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
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
OPTIONS
--attachable[=false] Enable manual container attachment
--aux-address=map[] Auxiliary IPv4 or IPv6 addresses used by Network driver
--config-from="" The network from which to copy the configuration
--config-only[=false] Create a configuration only network
-d, --driver="bridge" Driver to manage the Network
--gateway=[] IPv4 or IPv6 Gateway for the master subnet
-h, --help[=false] help for create
--ingress[=false] Create swarm routing-mesh network
--internal[=false] Restrict external access to the network
--ip-range=[] Allocate container ip from a sub-range
--ipam-driver="default" IP Address Management Driver
--ipam-opt=map[] Set IPAM driver specific options
--ipv6[=false] Enable IPv6 networking
--label= Set metadata on a network
-o, --opt=map[] Set driver specific options
--scope="" Control the network's scope
--subnet=[] Subnet in CIDR format that represents a network segment
SEE ALSO
docker-network(1)