As a wild guess, you're on a Windows PC of some description, and you've got more than one ORACLE_HOME? Does your TNSPING provide any more info: Used parameter files: c:\oracle\ora92\network\admin\sqlnet.ora or something like that? If it is a PC, you could try looking in the registry for the setting of TNS_ADMIN Hope that helps Simon Anderson > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Jonathan Knight > Sent: 18 January 2006 15:51 > To: Oracle Mailing List > Subject: TNS Resolution > > I have a strange (to me anyway) problem with TNS. > > Connecting with SQL*Plus, SQL*Navigator, TOAD: I get > "ORA-12154: TNS:could not resolve service name" > > But, tnsping returns in 100-130 msecs. ?!?!?! > > I'm confused. Any thoughts? > > Thanks, > Jon Knight -- //www.freelists.org/webpage/oracle-l