Networking allows you to create your favorite network topology for your containers, all with simple Docker commands. Let's go through a very simple example with 3 containers and 2 networks. Container 1 is in the first network, container 3 in the second. Container 2 shall be in both networks. We will verify that container 2 can reach all other containers, but containers 1 and 3 can not talk to each other.

• docker network create -d bridge mynet: create a new network called "mynet"
• docker network create -d bridge myothernet: create a second network called "myothernet"
• open 3 terminal windows and run:
• docker container run -it --rm --name c1 --network mynet alpine sh: create container 1
• docker container run -it --rm --name c2 --network mynet alpine sh: create container 2
• docker container run -it --rm --name c3 --network mynet alpine sh: create container 3
• Inside c2: ping <ip_c1> and ping c1 should work, ping c3 should not. Note we can use the IP or DNS name for the containers. You can find out the IP for instance with docker container inspect c1.
• docker network connect myothernet c2: now connect container "c2" also to "myothernet"
• Inside c2: ping <ip_c1> and ping c1 should work, ping c3 should now work as well
• Inside c3: ping c1 does not work
• Inside c1: ping c3 does not work

Don't forget to clean up when you are done.