This exception might occur when a remote application tries to register itself as an observer/listener with the Web NMS server running in a Linux machine.

Cause :
When registering for observer/listener, the RMI Registry uses the IP address specified in /etc/hosts. If the entry in /etc/hosts of the server machine is of the form

127.0.0.1  <Server HostName> localhost.localdomain localhost

the Connect exception would occur.

Solution :
To solve this problem,

• Stop the Web NMS server
• Remove the <Server HostName> entry from /etc/hosts. The entry should only be 
  127.0.0.1  localhost.localdomain localhost
• Restart the network of the server machine by executing the following commands from /etc/hosts/rc.d/init.d directory :
  ./network stop
  ./network start
• Start the Web NMS server and connect the client.