Thanks again for the many replies. I'm learning a lot about Net8. The good news is that the issue has been resolved ... I can now connect. The bad news it that I don't understand why. If anyone can offer any reason from the below, it would be appreciated. But, it's not necessary. We're all more than busy. Thanks again! Jon > Did you try setting TNS_ADMIN to the same path as shown below > for SQL*Navigator, and then seeing if tnsping still works? > > E.g. > > C:\>set TNS_ADMIN=C:\ora817NT\network\ADMIN > C:\>tnsping your_service Yes, I can still tnsping the service. As an aside, I can edit the connect string in the tnsnames.ora file and the changes are displayed when I tnsping, so I know it's got the right tnsnames.ora file. > How about reading some manuals, bozo? Manual will tell > you what TNS_ADMIN is for and where is the directory you > should be looking for. I haven't read the manual, but I have read the section describing TNS_ADMIN and have researched it via Google. I understand that it overrides all other methods for determining which tnsnames.ora file to use. Is this correct? > An ORA-12154 is a client side configuration error. I see > that you ping clsdev.world When you try to connect with > sql_navigator do you also specify clsdev.world, or just > clsdev? What's the content of your sqlnet.ora? Here are the contents of my sqlnet.ora ... AUTOMATIC_IPC = OFF TRACE_LEVEL_CLIENT = ADMIN names.directory_path = (TNSNAMES) names.default_domain = world name.default_zone = world SQL*Navigator displays the entry a little differently because of my TNS entry, shown here: CLSDEV,CLSDEV.WORLD = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = ud505)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = clsdev.world) ) ) So, SQL*Nav shows the whole "CLSDEV,CLSDEV.WORLD" in a drop-down. This was new to me, but another user here has it setup that way so I tried it. It seems that tnsping can still reach both CLSDEV & CLSDEV.WORLD (P.S. I've confirmed that there are no other entries in tnsnames.ora file that even contain the string "clsdev".) When I change the entry to read as below, I continue to get "ORA-12154: TNS:could not resolve service name" CLSDEV = (DESCRIPTION ... Interestingly, when I change the entry to read as below, then I can get in !?!?!? CLSDEV.WORLD = (DESCRIPTION ... I am rather confused. I understood that the tnsentry could be named anything one might want. In face, I have an entry named "FOOBAR.WORLD", also "MMISF15.corp.cefs.int". (Bby the way, both of these work.) Am I incorrect in this understanding? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- //www.freelists.org/webpage/oracle-l