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How do I resolve a "2016/03/09 14:48:23 Registration failed, 402. Retry in 1 seconds" error when starting the Docker Cloud Agent?


The Docker Cloud Agent is not able to connect remotely to Docker Cloud. To fix the issue, verify the correct ports are opened in any firewalls.


A2016/03/09 14:48:23 Registration failed, 402. Retry in 1 secondserror occurs when starting the Docker Cloud Agent.


This error may be caused by the host's firewall configuration. Verify that the firewall has been disabled or that the following ports are opened:

  • Required
    • 6783/tcp and 6783/udp for the node to join the private overlay network for communicating with containers on other nodes.
  • Recommended
    • 2375/tcp: for Docker Cloud to communicate with the Docker daemon running on the node. If port 2375 is not accessible, Docker Cloud will attempt to communicate with node through a secure reverse tunnel.
    • Of course, any ports used by the application will also need to be open.