1, the connection database shows no listener, first check whether the server's Oracle monitoring service is turned on, service name: Oracleoradb11g_home1tnslistener (may not be exactly the same in the specific environment, but look for Tnslistener is right)
2, local use 127.0.0.1 can be connected, but the use of native IP display no monitoring, use other machine connection is also no monitoring, first troubleshooting firewall problems
3, after the firewall is still not resolved, then the source of the problem: Oracle Listener.ora File
Workaround:
Listener.ora file path: F:\app\Administrator\product\11.2.0\dbhome_1\NETWORK\ADMIN\listener.ora (the specific installation path may be different, Please follow your own installation path), you need to restart the monitoring service after the modification
Some other tips for solving the process:
1, CMD can use the command:
Lsnrctl Stop Monitoring Service
Lsnrctl Start monitoring Service
Lsnrctl Reload Restart monitoring service
Lsnrctl Status View Monitoring service state
Tnsping IP to see if the listening service for this IP is normal for example: Tnsping 192.168.20.25
2, can use Sqlplus to enter the database to operate (in the case of a variety of tools can not connect to the database, Sqlplus is still firm)
Show parameter Listen view the configuration of the listener in the database
Alter system set local_listener= ' (ADDRESS = (PROTOCOL = TCP) (HOST = localhost) (PORT = 1521)) ' (modify parameters in the listening configuration list, parameters in quotation marks are only examples)
In any case, can not connect to the database, display no listening, after this step modification, the machine using 127.0.0.1 to connect to the database, but other machines and the use of IP is still unable to connect, and then the previous step of the operation
Other gains:
1, some of the machine is not recognized localhost, so try to use 127.0.0.1
2, Plsql will read the F:\app\Administrator\product\11.2.0\dbhome_1\NETWORK\ADMIN\tnsnames.ora file
3, after modifying the Listener.ora file, if the service fails to start (prompting the service did not report any errors), then it is likely that the Listener.ora file somewhere in the wrong, such as missing a parenthesis or something
ORACLE11G is switched on, but the remote connection still has no listening resolution process