docker network create

Estimated reading time:

8 minutes

Description

Create a network

Usage

docker network create [OPTIONS] NETWORK

Options

Name, shorthandDefaultDescription--attachable

API 1.25+

Enable manual container attachment--aux-addressAuxiliary IPv4 or IPv6 addresses used by Network driver--config-from

API 1.30+

The network from which copying the configuration--config-only

API 1.30+

Create a configuration only network--driver , -dbridgeDriver to manage the Network--gatewayIPv4 or IPv6 Gateway for the master subnet--ingress

API 1.29+

Create swarm routing-mesh network--internalRestrict external access to the network--ip-rangeAllocate container ip from a sub-range--ipam-driverIP Address Management Driver--ipam-optSet IPAM driver specific options--ipv6Enable IPv6 networking--labelSet metadata on a network--opt , -oSet driver specific options--scope

API 1.30+

Control the network’s scope--subnetSubnet in CIDR format that represents a network segment

Parent command

CommandDescriptiondocker networkManage networks

Related commands

Extended 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:

• Access to a key-value store. Engine supports Consul, Etcd, and ZooKeeper (Distributed store) key-value stores.
• A cluster of hosts with connectivity to the key-value store.
• A properly configured Engine daemon on each host in the cluster.

The dockerd options that support the overlay network are:

• --cluster-store
• --cluster-store-opt
• --cluster-advertise

To 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.

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.

$ 
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.

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:

OptionEquivalentDescriptioncom.docker.network.bridge.name-bridge name to be used when creating the Linux bridgecom.docker.network.bridge.enable_ip_masquerade--ip-masqEnable IP masqueradingcom.docker.network.bridge.enable_icc--iccEnable or Disable Inter Container Connectivitycom.docker.network.bridge.host_binding_ipv4--ipDefault IP when binding container portscom.docker.network.driver.mtu--mtuSet 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.

ArgumentEquivalentDescription--gateway-IPv4 or IPv6 Gateway for the master subnet--ip-range--fixed-cidrAllocate IPs from a range--internal-Restrict external access to the network--ipv6--ipv6Enable IPv6 networking--subnet--bipSubnet 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