On 3 separate 64 HP boxes running hpux 11, I have 3
instances of Oracle 64 bit. (one db per server)

From my desktop PC, I can connect to 2 of them with
my tnsnames.ora file looking like this :

(ADDRESS = (COMMUNITY = tcp.world)
(Host = server1.mycompany.com ) (Port = 12345 )

and I can change the 2nd to last line to :


and it still works.

But, connecting to one of the databases with my tnsnames file
having the 'service_name = ' gives me a ORA-12504 error.

Now, I know that the simple fix is to change my tnsnames.ora file and I have done that. But I am interested in this from
an educational standpoint...

I think all of my databases are setup on my servers the same
way. They are all running the same version of the database,
and the same version of the listener. What could it be?

thanks in advance!