Node Manager is not reachable Error in Weblogic Admin console

We might get below error as well,

For server <fmw managed server>, the Node Manager associated with machine <machine Name> is not reachable.

All of the servers selected are currently in a state which is incompatible with this operation or are not associated with a running Node Manager or you are not authorized to perform the action requested. No action will be performed.

Security:090476]Invalid/unknown SSL header was received from peer <hostname> during SSL handshake.

Solution :-  Follow the below steps.

Step 1:-

Login to Weblogic Admin Console à Click on ‘Servers’ à Click on ‘Admin Server’ or corresponding managed server à SSL àAdvanced à Set ‘Hostname Verification’ to ‘None’.

Step 2:-

Login to Weblogic Admin Console à Click on ‘Machines’ à Click on <machine name> à Node Manager à Select ‘Type’ as ‘Plain’.

Step 3:-

Login to the Machine with oracle user à Go to the below path for node manager configuration.

#cd /u01/app/oracle/product/fmw11g/wlserver_10.3/common/nodemanager/

#vi nodemanager.properties

Add below entry in the file and save it.

SecureListener=false

After performing above three steps, start the node manager.