B. TNS-12500 on a Unix Server ---------------------------- A TNS-12500 on a Unix server is almost always alinking problem with the listener or the oracleexecutable.Other issues may include permissions orenvironment settings.1.Check to make sure the TNS Listener is linked properly.Go to the $ORACLE_HOME/bin directory and run the'adapters' command on'tnslsnr'.For example:adapters tnslsnrYou should see output similar to the following:Net8 Protocol Adapters linked with tnslsnr are:BEQ Protocol Adapter IPC Protocol Adapter TCP/IP Protocol Adapter RAW Protocol AdapterNet8 Naming Adapters linked with tnslsnr are:Oracle TNS Naming Adapter Oracle Naming AdapterIf you do not see any output under the "Protocol Adapters"section then your platform is probably using sharedlibraries such that the network code is dynamically loaded.In this case locate the shared library that is used by theclient (typically the libclntsh.so library in$ORACLE_HOME/lib). Locating shared libraries is platformspecific.Eg: On Solaris:
$ ldd tnslsnr
may show libclntsh.so.1.0 =>
/u2/app/oracle/product/V805/lib/libclntsh.so.1.0Try the adapters command on the shared library.If your platform does not use shared libraries butthere is no output try to grep for the protocol symbolin the executable manually. For example:strings tnslsnr | grep nttiniNttini is the symbol for TCP/IP in both SQLNet V2 andNet8.Other protocol symbols are as follows:Protocol Adapter Symbol ---------------- ------TCP/IP
nttini DECNET
ntdini LU 6.2
ntlini SPX
ntsini IPC
ntusini BEQ
ntpiniIf you still do not get any output manually relink theexecutable as follows:Go to the $ORACLE_HOME/network/lib directory and executethe following command:make -f ins_network.mk installOn Oracle 8.1.x you can simply type 'relink network' atthe operating system prompt.By re-running the commands above your executable shouldhave a protocol adapter linked with it. Your connectionmay work now.2.Check to make sure the Oracle executable is linkedproperly.Go to the $ORACLE_HOME/bin directory and run the'adapters' command on 'oracle'.For example:adapters oracleYou should see output similar to the following:Net8 Protocol Adapters linked with Oracle are:BEQ Protocol Adapter IPC Protocol Adapter TCP/IP Protocol Adapter RAW Protocol AdapterNet8 Naming Adapters linked with Oracle are:Oracle TNS Naming Adapter Oracle Naming Adapter If you do not see any output under the "Protocol Adapters"section check for the use of shared objects as describedabove. Again you may need to grep for the protocol symbolin the executable manually.For example:nm oracle | grep nttiniIf you still do not get any output manually relink theexecutable as follows:Go to the $ORACLE_HOME/rdbms/lib directory and execute thefollowing command:
make -f ins_rdbms.mk installOn Oracle 8.1.x you can simply type in 'relink oracle'from the oracle_home/bin directory.By re-running the commands above your executable shouldhave a protocol adapter linked with it.3.Check the permissions on the tnslsnr and Oracleexecutables.Go the $ORACLE_HOME/bin directory.Typing 'ls -l tnslsnr'should yield the following output:-rwsr-xr-x oracle dbaTyping in 'ls -l oracle' should yield the same output:-rwsr-xr-x oracle dbaIf the permissions are different then change them withthis command:chmod 4755 tnslsnr
or chmod 4755 oracleIf the owner is incorrect, change it using this command:chown oracle tnslsnr
or chown oracle oracleRestart the listener and Oracle so the changes to theexecutables will take effect.4.Check Environment VariablesMake sure ORACLE_HOME and ORACLE_SID values are correct. You may also want to make sure LD_LIBRARY_PATH is setcorrectly as well.
