Kafka错误“Network is unreachable”和“larger than available brokers”

确定Kafka安装和启动正确，ZooKeeper可以查到所有的Brokers，但执行：
kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 3 --partitions 1 --topic my-replicated-topic
遇到如下错误：
java.net.SocketException: Network is unreachable
        at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
        at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
        at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361)
        at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1141)
Error while executing topic command : replication factor: 3 larger than available brokers: 0
[2017-06-26 17:25:18,037] ERROR org.apache.kafka.common.errors.InvalidReplicationFactorException: replication factor: 3 larger than available brokers: 0


这个问题可能是broker的配置文件server.properties中的配置项zookeeper.connect指定了kafka的zookeeper的根目录，如：
zookeeper.connect=192.168.31.32:2181,192.168.31.33:2181/kafka


这个时候，命令行参数“--zookeeper”的值也需要带上根目录，否则就会报这个错误，正确做法是：
kafka-topics.sh --create --zookeeper localhost:2181/kafka --replication-factor 3 --partitions 1 --topic my-replicated-topic