java.net.BindException: Cannot assign requested address
    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 io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:127)
    at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:554)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1258)
    at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:512)
    at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:497)
    at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:980)
    at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:250)
    at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:363)
    at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:418)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:449)
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:873)
    at java.lang.Thread.run(Thread.java:745)

#
# hosts     This file describes a number of hostname-to-address
#       mappings for the TCP/IP subsystem.  It is mostly
#       used at boot time, when no name servers are running.
#       On small systems, this file can be used instead of a
#       "named" name server.  Just add the names, addresses
#       and any aliases to this file...
#
# By the way, Arnt Gulbrandsen <agulbra@nvg.unit.no> says that 127.0.0.1
# should NEVER be named with the name of the machine.  It causes problems
# for some (stupid) programs, irc and reputedly talk. :^)
#

# For loopbacking.
127.0.0.1       localhost
127.0.0.1       localhost.localdomain localhost

# End of hosts.