DSE won't start because cannot bind to port 8609

In rare occasions, DSE will fail to start with the following exception on system.log:

INFO  [main] 2018-06-07 05:32:27,547  LeaseProtocol.java:92 - Registered LeaseProtocol 
INFO  [main] 2018-06-07 05:32:27,551  InternalQueryRouterProtocol.java:53 - Registered InternalQueryRouterProtocol 
INFO  [main] 2018-06-07 05:32:28,647  RemoteMessageServer.java:76 - Starting internode-messaging internal message server on [/10.200.43.10]:8609 
ERROR [main] 2018-06-07 05:32:28,719  CassandraDaemon.java:709 - Exception encountered during startup java.net.BindException: Address already in use
         at sun.nio.ch.Net.bind0(Native Method) ~[na:1.8.0_144]
         at sun.nio.ch.Net.bind(Net.java:433) ~[na:1.8.0_144]
         at sun.nio.ch.Net.bind(Net.java:425) ~[na:1.8.0_144]
         at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223) ~[na:1.8.0_144]
         at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) ~[na:1.8.0_144]
         at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:125) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:485) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1094) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:428) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:414) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:897) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:198) ~[netty-all-4.0.34.Final.jar:4.0.34.Final
         at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:349) ~[netty-all-4.0.34.Final.jar:4.0.34.Final
         at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:358) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:357) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137) ~[netty-all-4.0.34.Final.jar:4.0.34.Final]
         at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_144] 

The problem stems from DSE Search not being able to bind to port 8609 for inter-node communications.

Execute the following commands to free the socket

• sudo service dse stop
• sudo kill -9 $(sudo lsof -i :8609 | awk '!/PID/ {print $2}' | sort -u)
• sudo service dse start
• Try restarting DSE
• Should that still not work, try rebooting the node
• If DSE still refuses to start with the same error to bind to port 8609, follow these recommendations from redhat for port 8906