Listener refused the connection with the following error: ORA-12505

Question

Hello,
Listener refused the connection with the following error: ORA-12505, TNS:listener does not currently know of SID given in connect descriptor The Connection descriptor used by the client was: 127.0.0.1:1521:XE Windows XP + Oracle 10.1.0.20
I checked my *.ora files and found the host 127.0.0.1 but I noted by running netstat command on dos prompt that most of my ports are captured by www.360.cn including 1521
when am trying to shutdown then the following message appears:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not existsThanks & best regards

Answer 1

Hi,
[oracle@myoramachine ~]$ oerr ora 12505
12505, 00000, "TNS:listener does not currently know of SID given in connect descriptor"
// *Cause:  The listener received a request to establish a connection to a
// database or other service. The connect descriptor received by the listener
// specified a SID for an instance (usually a database instance) that either
// has not yet dynamically registered with the listener or has not been
// statically configured for the listener. This may be a temporary condition
// such as after the listener has started, but before the database instance
// has registered with the listener.
// *Action:
//  - Wait a moment and try to connect a second time.
//  - Check which instances are currently known by the listener by executing:
//    lsnrctl services <listener name>
//  - Check that the SID parameter in the connect descriptor specifies
//    an instance known by the listener.
//  - Check for an event in the listener.log file.
[oracle@myoramachine ~]$1. Check lsnrctl services <listener name>
2. Check tnsping output:
tnsping MYORACLE
3. Check connectivity to the machine where your Oracle Server resides to port ( I assume 1521):
telnet <your_machine> 1521
4. In case you're not able to connect to the Oracle Server - I'd investigate it in a few directions:
     - network infrastructure problem
     - some disturbing process(es) / virus(es) on Oracle Server itself
     - firewall issue
Good luck!
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