Networking with Standalone Docker Containers: Default Bridge Network

--- title: Networking with standalone containers description: Tutorials for networking with standalone containers keywords: networking, bridge, routing, ports, overlay aliases: - /network/network-tutorial-standalone/ --- This series of tutorials deals with networking for standalone Docker containers. For networking with swarm services, see [Networking with swarm services](/manuals/engine/network/tutorials/overlay.md). If you need to learn more about Docker networking in general, see the [overview](/manuals/engine/network/_index.md). This topic includes two different tutorials. You can run each of them on Linux, Windows, or a Mac, but for the last one, you need a second Docker host running elsewhere. - [Use the default bridge network](#use-the-default-bridge-network) demonstrates how to use the default `bridge` network that Docker sets up for you automatically. This network is not the best choice for production systems. - [Use user-defined bridge networks](#use-user-defined-bridge-networks) shows how to create and use your own custom bridge networks, to connect containers running on the same Docker host. This is recommended for standalone containers running in production. Although [overlay networks](/manuals/engine/network/drivers/overlay.md) are generally used for swarm services, you can also use an overlay network for standalone containers. That's covered as part of the [tutorial on using overlay networks](/manuals/engine/network/tutorials/overlay.md#use-an-overlay-network-for-standalone-containers). ## Use the default bridge network In this example, you start two different `alpine` containers on the same Docker host and do some tests to understand how they communicate with each other. You need to have Docker installed and running. 1. Open a terminal window. List current networks before you do anything else. Here's what you should see if you've never added a network or initialized a swarm on this Docker daemon. You may see different networks, but you should at least see these (the network IDs will be different): ```console $ docker network ls NETWORK ID NAME DRIVER SCOPE 17e324f45964 bridge bridge local 6ed54d316334 host host local 7092879f2cc8 none null local ``` The default `bridge` network is listed, along with `host` and `none`. The latter two are not fully-fledged networks, but are used to start a container connected directly to the Docker daemon host's networking stack, or to start a container with no network devices. This tutorial will connect two containers to the `bridge` network. 2. Start two `alpine` containers running `ash`, which is Alpine's default shell rather than `bash`. The `-dit` flags mean to start the container detached (in the background), interactive (with the ability to type into it), and with a TTY (so you can see the input and output). Since you are starting it detached, you won't be connected to the container right away. Instead, the container's ID will be printed. Because you have not specified any `--network` flags, the containers connect to the default `bridge` network. ```console $ docker run -dit --name alpine1 alpine ash $ docker run -dit --name alpine2 alpine ash ``` Check that both containers are actually started: ```console $ docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 602dbf1edc81 alpine "ash" 4 seconds ago Up 3 seconds alpine2 da33b7aa74b0 alpine "ash" 17 seconds ago Up 16 seconds alpine1 ``` 3. Inspect the `bridge` network to see what containers are connected to it.

This document provides tutorials on networking standalone Docker containers, contrasting with swarm service networking. It covers using the default 'bridge' network (suitable for basic setups) and creating user-defined bridge networks (recommended for production). The tutorial demonstrates starting two Alpine containers on the same Docker host and examining their communication via the default bridge network.