My client SqlPlus uses TNSNAMES to connect to the Ora817 db. One name is ORCL configured as dedicated connection and the other is NETORCL configured as shared connection. The other connection information is the same (ip, port, sid, etc).
However, the dedicated connection works fine, and the shared connection gives error ORA-12545, "Connection failed, Target host or object doesn't exist". Both connections used to work fine. The only thing I can think of is the network DNS server change. But why does the dedicated connectin work and the shared conn not? What configuration parameter affects the difference?