A Docker Subnet Overlap Can Keep Requests Away from the Proxy
Compare the requesting namespace's route with Docker's bridge ranges before changing the corporate proxy account.
A container on 172.17.0.0/16 can treat a corporate proxy at 172.17.14.133 as a local Docker neighbour. Its request then follows the bridge route instead of reaching the corporate network.
Inspect the route in the network namespace making the request. A Windows host route table alone does not describe every route inside Docker Desktop's Linux VM or a container.
| Docker setting | Network affected |
|---|---|
| bip | The default bridge's address and prefix |
| default-address-pools | Automatically allocated subnets for newly created networks |
Choose a non-overlapping range by comparing corporate, VPN, host and existing container networks. Changing the pool for future networks does not renumber existing ones.
Plan the affected network and container recreation with the workloads; address changes can break active connections. Resolving one overlap does not require disabling the bridge entirely.
Once the request reaches the intended listener, its protocol and authentication can be evaluated normally. A password change cannot fix this earlier route selection.