zookeeper集群安装的奇怪现象

zookeeper：配置的集群信息是domain：端口2888：端口3888；  domain为内网静态ip；每次启动都不能相互连接报错误：

[myid:3] - WARN  [WorkerSender[myid=3]:QuorumCnxManager@382] - Cannot open channel to 1 at election address zook1/10.100.20.73:3888

java.net.ConnectException: Connection refused

at java.net.PlainSocketImpl.socketConnect(Native Method)

at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)

at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)

at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

at java.net.Socket.connect(Socket.java:579)

at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:368)

at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:341)

at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:449)

at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:430)

at java.lang.Thread.run(Thread.java:745)

修改了下：将hosts文件中配置了：外网ip  domain；  内网ip  domain；  重新启动zookeeper集群，就能正常连接；

诡异的是：我重新删除hosts文件中的配置：外网ip  domain 删除，  然后重启zookeeper集群，竟然能正常连接。。。。

汗颜！！！！！！！！！！！！！！！！！！我测试了几遍   诡异诡异？？啥原因呢?部署了两套zookeeper集群都是这现象！！

/etc/hosts文件配置后，不是立马生效么？？？？？？？？？？？？？？？？？？？