docker network create

Create a network

Usage

$
 
docker network create 
[
OPTIONS] NETWORK

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

Parent command

Command
Description

docker network
Manage networks

Related commands