Re: My TNS listener stopped working

And make sure that the environment variables such as oracle_sid, oracle_home, oracle_base, etc. are all pointing where they are supposed to.

Daniel Morgan

Patrick Meyer wrote:

> I am confused by the symptoms you describe. The "ORA-12543:
> TNS:destination host unreachable" indicates that the client
> can not find the host on the network. Yet, you say that a TNSPING
> replies "OK". For the TNSPING to work, the client had to
> reach the listener and get a positive respone from the listener. As far
> as I know, this doesn't say anything about the state
> of the database, just that the listener is available and listening for
> the SID indicated in the TNS_NAMES.ora file.
>
> I would try to ping the Host from the Client and then the try to ping
> the client from the host. This will establish that
> the network is functioning. If that is successful, then run tnsping on
> the client and see if it's successful. If all that works,
> then is it possible that there are multiple Oracle clients installed on
> the client PC? Use find to see if there are more than
> one tnsnames.ora files on the client. If you are still having problems,
> post the results and someone will surely follow up
> on them.
>
> HTH,
> Patrick
>
> "Mike Harrison" <harrisonm7_at_home.com> wrote in message
> news:471417c6.0204120704.3f52f4bf_at_posting.google.com...
>
> > The TNS Listener for our Oracle 8.1.6 (NT4 sp6) server seems to have
> > stopped working all of a sudden. Nothing happened on the server that
> > I'm aware, but now all I get is
> >
> > ORA-12543: TNS:destination host unreachable
> >
> > when I try to log into the database with SQLPLUS. The listener's log
> > file seems to indicate that the connection was established:
> >
> > 12-APR-2002 10:55:07 *
> > (CONNECT_DATA=(SERVICE_NAME=oracle8.world)(CID=(PROGRAM=c:\orant\bin\SQLPLUS.EXE)(HOST=HOSTNAMEDELETED)(USER=USERNAME)))
> > * (ADDRESS=(PROTOCOL=tcp)(HOST=xx.xx.xx.xx)(PORT=1249)) * establish *
> > oracle8.world * 0
> >
> > The entry in the tnsnames.ora:
> >
> > ORACLE8 =
> > (DESCRIPTION =
> > (ADDRESS_LIST =
> > (ADDRESS = (PROTOCOL = TCP)(HOST = servername)(PORT = 1521))
> > )
> > (CONNECT_DATA =
> > (SERVICE_NAME = oracle8.world)
> > )
> > )
> > What would be the cause of this problem? I can log into the database
> > with sqlplus from the server itself, just not from a client. I haven't
> > changed the tnsnames.ora or listener.ora file on the server at all. I
> > can TNSPING the server and it says "OK". I've tried stopping and
> > starting the TNS listener to no avail. Everything was working fine
> > with this database yesterday.
>
> --
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Received on Fri Apr 19 2002 - 14:07:58 CDT