Where does sql*net get hostname in nttbnd2addr (MTS)

We had an issue recently where we coudln't connect to a server and would get an ORA-12545. Since I couldn't really analyze it until recently, we assumed that it was the firewall. Today, after making sure that high ports are accessible both ways, i enabled tracing, and saw that sql*net was looking up a name, but not a fully qualified name. After adding the name to /etc/hosts, we were able to connect w/o a problem, however, how do I make sure oracle passes back a fully-qualified name? (by passing back, I mean, that initially client was connecting to a fully qualified name, but then mts was redirecting to connect to another name, initially the client was connecting to a virtual IP--this is a clustered environment; so tnsping works; dedicated connection works; MTS didn't)

Here's an error from the log:
[09-JUN-2003 11:51:49:712] nttbnd2addr: looking up IP addr for host:
dragon1
[09-JUN-2003 11:51:49:760] nttbnd2addr: *** hostname lookup failure!
***
[09-JUN-2003 11:51:49:760] nttbnd2addr: exit

This is Solaris/Oracle 8.1.7.4. Client was actually a linux machine, but I don't think it matters.

.......
We use Oracle 8.1.7.4 on Solaris 2.7 boxes remove NSPAM to email Received on Mon Jun 09 2003 - 14:28:28 CDT