Cause: The address specified is not valid, or the program being connected to does not exist.
Action: Ensure the ADDRESS parameters have been entered correctly; the most likely incorrect parameter is the node name. Ensure that the executable for the server exists (perhaps “oracle” is missing.) If the protocol is TCP/IP, edit the TNSNAMES.ORA file to change the host name to a numeric IP address and try again.
Start Debugging with following steps:
• making sure that your listener is running (lsnrcrl status)
• Testing connectivity with ping, and then tnsping.
• verifying connectivity via the DNS (e.g. /etc/hosts)
• trcroute host_name
• Make sure to check your tnsnames.ora parameters.