Network configuration (Engine)
Bind container ports to the host
The information in this section explains binding container ports within the Docker default bridge. This is a bridge network named bridge created automatically when you install Docker.
Note: The Docker networks feature allows you to create user-defined networks in addition to the default bridge network.
By default Docker containers can make connections to the outside world, but the outside world cannot connect to containers. Each outgoing connection will appear to originate from one of the host machine’s own IP addresses thanks to an iptables masquerading rule on the host machine that the Docker server creates when it starts:
$ sudo iptables -t nat -L -n ... Chain POSTROUTING (policy ACCEPT) target prot opt source
