k3d/docs/design/networking.md

Networking

• Related issues:
  • k3d-io/k3d #220

Introduction

By default, k3d creates a new (docker) network for every new cluster.
Using the --network STRING flag upon creation to connect to an existing network.
Existing networks won't be managed by k3d together with the cluster lifecycle.

Connecting to docker "internal"/pre-defined networks

host network

When using the --network flag to connect to the host network (i.e. k3d cluster create --network host), you won't be able to create more than one server node.
An edge case would be one server node (with agent disabled) and one agent node.

bridge network

By default, every network that k3d creates is working in bridge mode.
But when you try to use --network bridge to connect to docker's internal bridge network, you may run into issues with grabbing certificates from the API-Server.
Single-Node clusters should work though.

none "network"

Well.. this doesn't really make sense for k3d anyway ¯\_(ツ)_/¯