172.17.0.0/16 (Docker Default Bridge)
PrivateRFC 1918
172.17.0.0/16 at a glance
| CIDR block | 172.17.0.0/16 |
|---|---|
| First address | 172.17.0.0 |
| Last address | 172.17.255.255 |
| Total addresses | 65,536 |
| Subnet mask | 255.255.0.0 |
| Prefix length | /16 |
| Type | Private |
| Publicly routable | No |
| Defined in | RFC 1918 |
Open in CIDR calculator/16 subnet details
What is 172.17.0.0/16 used for?
172.17.0.0/16 is the subnet Docker assigns to its default bridge network (docker0), with the host at 172.17.0.1. It sits inside the private 172.16.0.0/12 range. If your office or VPN also uses 172.17.x.x, containers can lose access to it; change Docker's "bip" or "default-address-pools" setting.
Common subnets of 172.17.0.0/16
Overlaps and conflicts
- Inside 172.16.0.0/12
FAQ
How do I change the Docker default subnet 172.17.0.0/16?
Set "bip": "10.200.0.1/24" (or another free range) in /etc/docker/daemon.json for the default bridge, and default-address-pools for new networks, then restart Docker.
What is 172.17.0.1?
The host's address on the docker0 bridge. Containers on the default bridge use it as their gateway and can reach services on the host through it.