Docker
/Advanced
Overlay Network
Definition
A distributed network driver that creates a virtual network on top of multiple physical Docker hosts, allowing containers on entirely different physical servers to communicate securely as if they were on the same local switch.
Explain Like I'm New
A magic tunnel. Container A is on a server in New York. Container B is on a server in London. The Overlay network builds an encrypted tunnel over the public internet, allowing them to talk to each other securely over a private local IP address.
Real World Example
Used heavily in Docker Swarm and Kubernetes architectures. A 100-server cluster uses an Overlay network so the load balancer on Server 1 can route traffic to an API container randomly running on Server 87.
Common Use Cases
- •Container Orchestration
- •Multi-host clustering
Interview Questions
basic
- Which network driver allows containers on two completely different physical computers to communicate?
intermediate
- What underlying technology secures the traffic passing through a Docker Overlay network over the public internet?