Docker Network Basics

Docker Network Basics

In this lab you'll look at the most basic networking components that come with a fresh installation of Docker.

You will complete the following steps as part of this lab.

• Step 1 - The docker network command

• Step 2 - List networks

• Step 3 - Inspect a network

• Step 4 - List network driver plugins

Prerequisites

You will need all of the following to complete this lab:

• A Linux-based Docker Host running Docker 1.12 or higher

Step 1: The docker network command

The docker network command is the main command for configuring and managing container networks.

Run a simple docker network command from any of your lab machines.

docker network

The command output shows how to use the command as well as all of the docker network sub-commands. As you can see from the output, the docker network command allows you to create new networks, list existing networks, inspect networks, and remove networks. It also allows you to connect and disconnect containers from networks.

Step 2: List networks

Run a docker network ls command to view existing container networks on the current Docker host.

docker network ls

The output above shows the container networks that are created as part of a standard installation of Docker.

New networks that you create will also show up in the output of the docker network ls command.

You can see that each network gets a unique ID and NAME. Each network is also associated with a single driver. Notice that the "bridge" network and the "host" network have the same name as their respective drivers.

Step 3: Inspect a network

The docker network inspect command is used to view network configuration details. These details include; name, ID, driver, IPAM driver, subnet info, connected containers, and more.

Use docker network inspect to view configuration details of the container networks on your Docker host. The command below shows the details of the network called bridge.

docker network inspect bridge

NOTE: The syntax of the docker network inspect command is docker network inspect <network>, where <network> can be either network name or network ID. In the example above we are showing the configuration details for the network called "bridge". Do not confuse this with the "bridge" driver.

Step 4: List network driver plugins

The docker info command shows a lot of interesting information about a Docker installation.

Run a docker info command on any of your Docker hosts and locate the list of network plugins.

docker info

The output above shows the bridge, host, null, and overlay drivers.