When we talk about Docker Swarm, we need to introduce a new concept regarding networks: overlay networks. As we mentioned at the beginning of this chapter, a new network driver will be available because Docker Swarm will distribute all application components across multiple nodes. They have to be reachable no matter where they run. The overlay network will work over VXLAN tunnels using the User Datagram Protocol (UDP). We will be able to encrypt this communication, but some overhead should normally be expected.
The overlay network driver will create a distributed network across cluster nodes and automatically provides routing of packets to interconnect distributed containers.
When Swarm is first initialized, two networks are created:
- docker_gwbridge: This bridge network will connect all Docker daemons that are part of the cluster.
- ingress: This is an overlay network that will manage Docker Swarm services' control and data traffic. All the services will...