I installed a 10g R2 database on a standalone Solaris 9 box. We have
since hardened the machine, and have put it up on the network. Since
putting it up, I am not able to connect to the database remotely
(sqlplus, golden, toad, etc.). The error I receive is a

ORA-12564: TNS:connection refused

I have checked my tnsnames, listener.ora, and other config files --
nothing appears to be awry. Could this issue be connected to the fact
that the box did not have a FQDN when I installed. If so, is there a
way that I can remedy the issue now, or would it require a re-install?

Your help is appreciated....

//NC