# Troubleshooting

- Check the broker is Kafka 4.0+.
- Check bootstrap addresses are reachable.
- Check advertised listeners point back to reachable hosts.
- Use TLS only against TLS listeners.
- Use SASL only against SASL-enabled listeners.
- Enable `tracing` output in the application.
- Check topic metadata if partition lookup fails.
- Check group coordinator availability for consumer group errors.

