DOCKER(1)DOCKER(1)
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 create an overlay network. Unlike bridge
networks overlay networks require some pre-existing conditions before
you can create one. These conditions are:
o Access to a key-value store. Engine supports Consul, Etcd, and
Zookeeper (Distributed store) key-value stores.
o A cluster of hosts with connectivity to the key-value store.
o A properly configured Engine daemon on each host in the
cluster.
The dockerd options that support the overlay network are:
o --cluster-store
o --cluster-store-opt
o --cluster-advertise
To read more about these options and how to configure them, see "Get
started with multi-host network"
<https://docs.docker.com/engine/userguide/networking/get-started-
overlay/>.
It is also a good idea, though not required, that you install Docker
Swarm on to manage the cluster that makes up your network. Swarm
provides sophisticated discovery and server management 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.
Connect containers
When you start a container use the --network flag to connect it to a
network. This 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.
Specifying 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 -d 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.
$ docker network create -d overlay \
--subnet=192.168.0.0/16 \
--subnet=192.170.0.0/16 \
--gateway=192.168.0.100 \
--gateway=192.170.0.100 \
--ip-range=192.168.1.0/24 \
--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.
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.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 copying 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)
Docker Community Jun 2020 DOCKER(1)