Why Can’t I Connect to Kafka? | Troubleshoot Connectivity

This post details how to troubleshoot Kafka client connectivity issues by focusing on the `advertised.listeners` configuration. It explains the two-step connection process (initial bootstrap and subsequent broker connections) and highlights how misconfigurations in `advertised.listeners` can lead to connection failures. The article provides practical examples and solutions for common scenarios: client and Kafka on the same local machine, client and Kafka on different machines, and client and Kafka running in Docker containers. It emphasizes that `advertised.listeners` must return an address resolvable and accessible from the client machine.