I am using a db link to connect to a different database.

My problem is when I try to query an object database b using
select column from objectname@dblinkname

I get this error ORA-12638 Credential Retrieval failed.

But I am able to query connecting the session seperately.

So, only when using the dblink i get the above error.

Can anybody help me in this regard.

I checked TNSNAMES.ORA also i tried changing the SQLNET.ORA authentication parameter from NTS to NONE.It doesn't work.