安装zookeeper之后，使用默认配置启动服务时报端口被占用，默认端口是2181。
而且使用netstat -ano | findstr '2181'找不到占用端口的进程。
报错信息：
java.net.BindException: Address already in use: bind
at sun.nio.ch.Net.bind0(Native Method)
at sun.nio.ch.Net.bind(Net.java:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:67)
at org.apache.zookeeper.server.NIOServerCnxnFactory.configure(NIOServerCnxnFactory.java:687)
at org.apache.zookeeper.server.ZooKeeperServerMain.runFromConfig(ZooKeeperServerMain.java:143)
at org.apache.zookeeper.server.ZooKeeperServerMain.initializeAndRun(ZooKeeperServerMain.java:106)
at org.apache.zookeeper.server.ZooKeeperServerMain.main(ZooKeeperServerMain.java:64)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.initializeAndRun(QuorumPeerMain.java:128)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.main(QuorumPeerMain.java:82)
问题原因：
Win10预留了一部分端口，导致这些端口无法被使用。可以通过命令查看这些系统保留的端口号：
netsh interface ipv4 show excludedportrange protocol=tcp
