Unable to start node manager becuase of java.net.BindException: Address already in use

========================================================================
Applies to:
Weblogic Server: 10.3.6 and later
========================================================================
Problem Summary:
Trying to start node manager but couldn't able to because of java.net.BindException: Address already in use

Error:
<Jan 8, 2017 10:43:12 PM CST> <SEVERE> <Fatal error in NodeManager server>
java.io.IOException: The server is unable to create a server socket for listening. The address puruhost might be incorrect or another process is using port 25000: java.net.BindException: Address already in use
        at weblogic.nodemanager.server.NMServer.start(NMServer.java:351)
        at weblogic.nodemanager.server.NMServer.main(NMServer.java:529)
        at weblogic.NodeManager.main(NodeManager.java:31)
Caused by: java.net.BindException: Address already in use
        at java.net.PlainSocketImpl.socketBind(Native Method)
        at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:387)
        at java.net.ServerSocket.bind(ServerSocket.java:375)
        at java.net.ServerSocket.<init>(ServerSocket.java:237)
        at javax.net.ssl.SSLServerSocket.<init>(SSLServerSocket.java:181)
        at sun.security.ssl.SSLServerSocketImpl.<init>(SSLServerSocketImpl.java:140)
        at sun.security.ssl.SSLServerSocketFactoryImpl.createServerSocket(SSLServerSocketFactoryImpl.java:95)
        at weblogic.nodemanager.server.SSLListener.privilegedInit(SSLListener.java:134)
        at weblogic.nodemanager.server.SSLListener.access$000(SSLListener.java:33)
        at weblogic.nodemanager.server.SSLListener$1.run(SSLListener.java:97)
        at java.security.AccessController.doPrivileged(Native Method)
        at weblogic.nodemanager.server.SSLListener.init(SSLListener.java:94)
        at weblogic.nodemanager.server.NMServer.start(NMServer.java:349)
        ... 2 more

========================================================================
Root Cause:
Port number used by node manager process is being already used by some other process.

========================================================================
How to verify:
1. Login to host
2. Verify process which is using node manager port using
 /usr/sbin/lsof -i:port_num
 netstat -an | grep port_num
 e.g. /usr/sbin/lsof -i:25000
netstat -an | grep 25000

========================================================================
Resolution:
1. Once you find a process which is using Node manager port and can be killed, kill it using,
 kill -9 PID
2. Restart node manager using $DOMAIN_HOME/bin/startNodeManager.sh