https://www.cnblogs.com/xuliang666/p/11871389.html
在 config/server.properties 中 配置项
listeners
listeners就是主要用来定义Kafka Broker的Listener的配置项，用于本机监听。
advertised.listeners
advertised.listeners参数的作用就是将Broker的Listener信息发布到Zookeeper供客户端使用监听，是真正的对外代理地址。如果没有设置，会用listeners。
外部连接访问这个，需要设置这个值，
如 java/spring 代码连接kafka ，如果不设置advertised.listeners，就连接不上 报错：
Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
# The address the socket server listens on. It will get the value returned from
# java.net.InetAddress.getCanonicalHostName() if not configured.
# FORMAT:
# listeners = listener_name://host_name:port
# EXAMPLE:
# listeners = PLAINTEXT://your.host.name:9092
#listeners=PLAINTEXT://:9092
# Hostname and port the broker will advertise to producers and consumers. If not set,
# it uses the value for "listeners" if configured. Otherwise, it will use the value
# returned from java.net.InetAddress.getCanonicalHostName().
#advertised.listeners=PLAINTEXT://your.host.name:9092
advertised.listeners=PLAINTEXT://192.168.20.10:9092 # 配置了本机ip