url redirection

[dd_devils at hotmail.com]

I hope this is the right group to ask this...

I want to redirect a given url to a site on our server.
Both the new url and the real site's url point to our DNS server (which
is on the same machine as the site).
We have a Fedora server (with Ensim, but that does not matter at this
moment, unless someone knows how to set it up in Ensim).

In general, what should i do to set up redirection of www.site1.com to
www.site2.com in a way that www.site2.com will be in the browsers
addressbar after redirection.
Can this be accomplished by dns-setup or is this an Apache matter?

Thanks guys!
Let me know if I have to post more information...