How to set up domain mapping on my dev machine

Hi,

I'm trying to setup domain mapping on a test wordpress install on my dev machine.

I have a wamp setup and have created a main domain plus another one which is parked on a sub-domain of the main site:

domain1.dev -> domain1 (folder)
domain2.dev -> sub1.domain1.dev -> domain1/domain2 (folder)

I'm not sure that this is correct, but this is what I deduced from everything I've read so far.

I've tried to add domain2 to the domain mapping and multi domains plugins, but it appears that I haven't fully understood how these plugins or domain mapping in wordpress works, as domain2 doesn't appear in the My Sites menu, even though it does appear on the All Sites page.

Multi Domains gives the following message on the Multi Domains settings page:

Warning! Wildcard DNS for domain2.dev may not be configured correctly!

Unable to contact the random hostname (b45d97.domain2.dev).

Can anyone enlighten me about how to set up domain2, including what I need to do within Apache, so it will show it's own content when domain2.dev is typed into a browser?

Debbie