Multiple domains, same cache?

[Daniel Gary <dgary1980@xxxxxxxxx>]

Hey All,

Ok, so I have a quandary, I have a client who has multiple domains, some 
of which are just subdomains to the same vhost, running the same code, 
but from what I understand if I went to bob.test.dom and steve.test.dom, 
even if they return the exact same content they would get cached 
separately, which makes sense, how would squid know if they shouldn't. 
Unfortunately, I need it to cache them together, we have a mobile 
subdomain that gets random bouts of traffic, not enough to really 
populate a cache on its own fully, but has identical content to another 
subdomain which gets more than enough, and we don't want the server 
impacted by uncached content if possible.

Anyway I can get them using the same cached content without forcedomain 
or a rewrite/redirector?

Thanks,
-Daniel