Create: docker network create

In your compose files, you can join a network with:

service: 
	myservice: 
	
		networks: 
			- <network-name>
 
networks: 
	<network-name>: 
		external: true

Using the externalflag is recommended if you created the network externally.

Defaults

When not explicitly using networks in your docker compose file, Docker creates a default bridge network for all services in your docker compose configuration.