When I installed oracle 9.2i on redhat linux 9 I created usergroups for user
oracle as stated in the manuals
# groupadd dba
# useradd oracle
# mkdir /opt/oracle
# mkdir /opt/oracle/product/9.2.0/
# chown -R oracle:dba /opt/oracle

Now whatever I type at the sqlplus I get shared realm does not exist
even logging in as sysdba
sqlplus /nolog
connect as sysdba

I get connected to an idle instance

trying sqlplus oracle/oraclepassword@thenameofmydatabase I created with dbca
gets me the shared realm does not exist
I am at loggerheads what could be wrong, everything seemed to have installed
ok