Unstable connections, corporate firewalls, or VPNs can cause "unexpected EOF" (End of File) or connection timeouts.
Docker may fail to resolve the registry hostname (e.g., registry-1.docker.io ), often because of a faulty local DNS stub resolver.
Incorrect system time or missing CA certificates can lead to "failed to verify certificate" errors. docker download failed after attempts=6
Corruption in the local Docker cache or a stuck daemon process can trigger persistent failures. Problem/ problem pulling images - Docker Community Forums
If your environment requires a proxy, Docker must be explicitly configured to use it via environment variables like HTTP_PROXY and HTTPS_PROXY . Unstable connections, corporate firewalls, or VPNs can cause
If you are behind a corporate firewall, Docker requires a manual proxy configuration in the daemon settings.
Expired login tokens or insufficient permissions for private repositories can trigger retry loops. Step-by-Step Troubleshooting Solutions 1. Fix DNS Resolution (Most Common for Linux) Corruption in the local Docker cache or a
Reload and restart Docker: sudo systemctl daemon-reload && sudo systemctl restart docker . 3. Restart and Clear Cache
Verify connectivity by running ping hub.docker.com or curl -v https://registry-1.docker.io/v2/ .
[Service] Environment="HTTP_PROXY=http://example.com" Environment="HTTPS_PROXY=https://example.com" Use code with caution.