Networking

Default Network

Every container connects to a default bridge network. Containers on the same network can communicate using container names as hostnames.

No manual network configuration is needed for most development workflows.

Port Mapping

Expose container ports to your Mac with -p:

docker run -d -p 8080:80 nginx

The service is then accessible at localhost:8080 and <container-name>.arcbox:8080.

Port mappings are displayed in the container list and the Inspect tab.

Host Networking

Containers can reach services running on your Mac using the special hostname:

host.docker.internal

This resolves to your Mac's IP address as seen from inside the container. Useful for connecting to local databases, APIs, or other services during development.

Container-to-Container

Containers on the same user-defined network can reach each other by name:

docker network create my-net
docker run -d --name db --network my-net postgres
docker run -d --name app --network my-net my-app
# "app" can connect to "db" using hostname "db"

ArcBox provides built-in DNS resolution within Docker networks.

.arcbox Domains

Containers are also reachable from your Mac at <name>.arcbox. See Domains for details.

Managing Networks

Click Networks in the sidebar to view, create, and delete Docker networks. Each network shows its driver, subnet, and connected containers.

The default networks (bridge, host, none) cannot be removed.

VPN Compatibility

Some VPN clients modify the routing table in ways that break container networking. If containers lose internet access after connecting to a VPN, restart the runtime:

arcbox restart

Contact your VPN provider about split-tunnel configuration for long-term compatibility.