moby/libnetwork/docs/bridge.md

Bridge Driver

The bridge driver is an implementation that uses Linux Bridging and iptables to provide connectivity for containers It creates a single bridge, called docker0 by default, and attaches a veth pair between the bridge and every endpoint.

Configuration

The bridge driver supports configuration through the Docker Daemon flags.

Usage

This driver is supported for the default "bridge" network only and it cannot be used for any other networks.