301 redirect vs domain alias

[coog]

I did some searching on this but most of what i found on google was pretty old. So I thought I would ask here.

I have a client that just pushed about 15 domains to me and wants them all to point to the main site. I would typically just do a 301 but in this case the client does not want it to redirect, he wants the url to show as the the new domain(s).

Google webmaster guidelines states "Don't create multiple pages, subdomains, or domains with substantially duplicate content"

Are domain aliases considered duplicate content if they all point to the same site? I would say no, but what do I know :-)

Thanks

[sarah_may]

well if he wants the url to show as the the new domain(s) then legally it is possible only through rediretion and you need to use only 301 redirection.

[coog]

Sorry for not being more clear. Correct me if I'm wrong but lets say domain.com is the main domain and newdomain.com is the redirected one.

If you use a 301, when typing newdomain.com into the navigation bar it will take you to domain.com, the url in the navigation bar will change to "domain.com"

If you use an alias, when typing newdomain.com into the navigation bar it will take you to domain.com, and the url in the navigation bar will remain "newdomain.com"

He would prefer the latter as the new domains will stay in the nav bar when typed in.

Does that make more sense? I'm still on my first cup of coffee :-)

Thanks