Docker Core
The network driver could not program the published port mapping for the endpoint.
driver-failed-external-connectivityReviewed for reference consistency: August 11, 2026
The network driver could not program the published port mapping for the endpoint.
What driver-failed-external-connectivity Means
The driver-failed-external-connectivity error on the Docker Core indicates the network driver could not program the published port mapping for the endpoint.. This typically occurs due to the underlying bind failed because the host port is already taken.
When a container starts, the daemon asks the network driver to wire up published ports for the new endpoint. Failures at that step surface as the driver-failed-programming-external-connectivity line, typically followed by the underlying bind error that caused the wiring to fail.
How to fix driver-failed-external-connectivity
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Show the endpoint's current port wiring
The port mapping view displays which bindings succeeded for the container, framing what the driver still owed.
docker port <container>Review the host interfaces the bind targets
The brief address listing exposes which interfaces hold listeners, clarifying the requested bind's collision surface.
ip -brief address show
Technical Background
This line names the stage, not the root cause: endpoint programming failed, and the text appended after the endpoint identifier carries the actual reason, most often the same bind conflicts that surface standalone.
Docker's own workshop material reproduces exactly this wording for the everyday case of starting a second container while the first still holds the published port, which makes it one of the most-quoted long-form Docker errors.
Common Causes
- The underlying bind failed because the host port is already taken
- A firewall or NAT rule conflict blocked the driver's port programming
- The endpoint's network driver hit a host-level networking error
Typical Scenarios
- A publish request whose host side is already taken, reproduced during container start
- Compose bringing up several services whose fixed ports collide pairwise
- Restarting a container after the host networking stack changed underneath it
What to Know
Reading the tail after the endpoint identifier matters more than the headline: the appended kernel or proxy reason distinguishes a port conflict from a deeper driver failure on the same message template.
Frequently Asked Questions
Common questions about Docker driver-failed-external-connectivity error
Usually not. The overwhelming majority of occurrences end with a bind conflict in the appended text; the driver merely reported the failure.
It is the container's endpoint hash, letting the mapping failure be tied to one specific container on one specific network.
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