Docker Certified Associate Exam Course
Docker Engine Networking
Networking additional commands
Manage Docker networks beyond the basics. In this guide, you’ll learn how to list default networks, inspect their settings, connect or disconnect containers, and remove unused networks to keep your Docker environment clean.
Table of Contents
- Listing Default Networks
- Inspecting a Network
- Connecting and Disconnecting Containers
- Removing Networks
Listing Default Networks
Docker provides three built-in networks out of the box: bridge
, host
, and none
. Use the following command to see them:
docker network ls
Example output:
NETWORK ID NAME DRIVER SCOPE
599dcaf4e856 bridge bridge local
c817f1bca596 host host local
e6508d3404a3 none null local
You can also get a quick overview in tabular form:
Network Name | Driver | Scope | Description |
---|---|---|---|
bridge | bridge | local | Default network for standalone containers |
host | host | local | Containers share the host’s network namespace |
none | null | local | Containers have no network interfaces |
Note
The bridge network uses the 172.17.0.0/16
subnet by default, with gateway 172.17.0.1
assigned to the docker0
interface on the host.
Inspecting a Network
To dive deeper into a network’s configuration—such as its IPAM settings, subnets, gateways, and attached containers—run:
docker network inspect bridge
Sample output (abridged):
[
{
"Name": "bridge",
"Id": "599dcaf4e85648c3a111baa52b7530f097853b96485a8a3ffcd9088b20f0cb",
"Scope": "local",
"Driver": "bridge",
"IPAM": {
"Driver": "default",
"Config": [
{
"Subnet": "172.17.0.0/16",
"Gateway": "172.17.0.1"
}
]
},
"Containers": {
// attached container details
}
}
]
This output shows the network’s driver, IPAM configuration, and any containers currently connected.
Connecting and Disconnecting Containers
You can attach a running container to additional networks or remove it from one without restarting:
# Connect a container to a custom network
docker network connect custom-net my-container
# Disconnect a container from a network
docker network disconnect custom-net my-container
These commands make it easy to adjust a container’s network access on the fly.
Removing Networks
Clean up unused networks to avoid clutter:
# Remove a specific network
docker network rm custom-net
# Remove all unused networks
docker network prune
Warning
This will remove all networks not used by at least one container.
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