An AIX oracle 11g server is configured to use the remote os authentcation option for select few users. Everything works fine from the shell of the DB server (e.g. you type sqlplus / and login is successful). When connecting remotely from another system, this however, fails with invalid username/password error message. The usernames are the same on the DB system and on the remote system. The DB system is aix and remote - Linux.
P.S. Please don't mention the security risks, I know about it.
In your linux oracle client, did you configure the tnsnames.ora file to point to aix db server? if not you need to do that to establish a connection. You may need to set "remote_login_passwordfile" to "exclusive", bounce your database and recreate your password file... Please let me know the status once done..