moby/docs/userguide/networking/default_network/options.md

Quick guide to the options

Here is a quick list of the networking-related Docker command-line options, in case it helps you find the section below that you are looking for.

Some networking command-line options can only be supplied to the Docker server when it starts up, and cannot be changed once it is running:

• -b BRIDGE or --bridge=BRIDGE -- see

Building your own bridge

• --bip=CIDR -- see

Customizing docker0

• --default-gateway=IP_ADDRESS -- see

How Docker networks a container

• --default-gateway-v6=IP_ADDRESS -- see

IPv6

• --fixed-cidr -- see

Customizing docker0

• --fixed-cidr-v6 -- see

IPv6

• -H SOCKET... or --host=SOCKET... --

This might sound like it would affect container networking,

but it actually faces in the other direction:

it tells the Docker server over what channels

it should be willing to receive commands

like "run container" and "stop container."

• --icc=true|false -- see

Communication between containers

• --ip=IP_ADDRESS -- see

Binding container ports

• --ipv6=true|false -- see

IPv6

• --ip-forward=true|false -- see

Communication between containers and the wider world

• --iptables=true|false -- see

Communication between containers

• --mtu=BYTES -- see

Customizing docker0

• --userland-proxy=true|false -- see

Binding container ports

There are three networking options that can be supplied either at startup or when docker run is invoked. When provided at startup, set the default value that docker run will later use if the options are not specified:

• --dns=IP_ADDRESS... -- see

Configuring DNS

• --dns-search=DOMAIN... -- see

Configuring DNS

• --dns-opt=OPTION... -- see

Configuring DNS

Finally, several networking options can only be provided when calling docker run because they specify something specific to one container:

• -h HOSTNAME or --hostname=HOSTNAME -- see

Configuring DNS and

How Docker networks a container

• --link=CONTAINER_NAME_or_ID:ALIAS -- see

Configuring DNS and

Communication between containers

• --net=bridge|none|container:NAME_or_ID|host -- see

How Docker networks a container

• --mac-address=MACADDRESS... -- see

How Docker networks a container

• -p SPEC or --publish=SPEC -- see

Binding container ports

• -P or --publish-all=true|false -- see

Binding container ports

To supply networking options to the Docker server at startup, use the DOCKER_OPTS variable in the Docker upstart configuration file. For Ubuntu, edit the variable in /etc/default/docker or /etc/sysconfig/docker for CentOS.

The following example illustrates how to configure Docker on Ubuntu to recognize a newly built bridge.

Edit the /etc/default/docker file:

$ echo 'DOCKER_OPTS="-b=bridge0"' >> /etc/default/docker

Then restart the Docker server.

$ sudo service docker start

For additional information on bridges, see building your own bridge later on this page.