SQL*Plus: Release 184.108.40.206.0 - Production on Sun Aug 19 13:18:56 2007
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ORA-12532: TNS:invalid argument
In this case we can ping to remote host but not able to connect database which we have created on remote host.
Cause : Listener port is closed.May be a firewall policy make the issue.
Action : We need to open Listener port for communication .By default Listener port is 1521.