I am unable to connect Forms 6.0 with Oracle 8.1.7 (On windows 2000) from Client machine. Listner is started on Server. In sqlnet following error observed :
Tns error struct:
nr err code: 12206
TNS-12206: TNS:received a TNS error during navigation
ns main err code: 12545
TNS-12545: Connect failed because target host or object does not exist
ns secondary err code: 12560
nt main err code: 515
TNS-00515: Connect failed because target host or object does not exist
nt secondary err code: 1004
nt OS err code: 0
try pinging the machine...
ping machine_name/or ip address..
This way you can see if the machine is on....
then do tnsping < service name > .....
if these 2 steps are ok you must connect..........
This error (TNS-12545) generally refers to the host name being incorrect. check your listener.ora and tnsnames.ora to make sure they entries are correct.
And in the tnsping command you'll get the error/with address on your tnsnames.ora file compare it with the listener.ora on the server.
Start the database and listener from control panel>services.
The home directories of both should be differenet. First configure oracle server listener.ora and tnsnames according to your host machine and addreses. After that copy the folder "network" from Oracle server directory and paste it (overwrite) on the contents of network folder of developer 6.It will work fine. I myself soved that problem like this.
from client machine tnsping( and IP address) is ok. I have also use ping and IP address, it also ok
It might be an idea to do a sqlnet trace, the attached link may help