Database installation is complete, the server restart, ready to start the oracle database, Connect the conn/as sysdba error ORA - 12545: Connect failed because the target host or object does not exist, the host name and IP address are unmodified, listening can normal boot, corresponds to the hostname in/etc/hosts: no problem, the listener, ORA file host name no problem, which the great spirit encountered such a problem, guidance, the database is installed on the Linux, Linux IP xshell is through the network connection