Connection is refused or times out

Check

1. Confirm the client uses the current Nexo host and port.
2. Confirm the Nexo runtime is ready and listening.
3. Test DNS resolution from the client network.
4. Check firewalls, security groups, network policies, and load balancer health.
5. Confirm Nexo can reach the configured MongoDB upstream.
6. Compare with a controlled direct MongoDB connection.

Interpret

• Immediate refusal usually indicates no listener or a rejected network path.
• A timeout usually indicates routing, filtering, DNS, or an unreachable upstream.
• Intermittent failures may indicate readiness, capacity, or connection-lifecycle issues.

Do not disable TLS or authentication as a permanent diagnostic workaround.