Wordpress Multisite Subdomain

[Daniel L. Miller]

I have Wordpress currently setup with subdomain multisite.  I have 
multiple domains that are aliases for a primary domain.  With the rules 
I have in place, going to one of the secondary domains results in a hard 
redirect to my primary.  Example:

Enter http://secondarydomain.com in the browser.
Get redirected to http://primarydomain.com.

Is this the only way I can have it work?  My preference would be to have 
the server name remain the "secondary" name as entered - so it appears 
to be multiple discreet sites.
-- 
Daniel