Redirect with multisite

Hi,
I was wondering what the best way is to do a redirect if you have a WordPress multisite environment.

I have a website and have a second additional domainname.
What I can do is add the second domain in the Domain Mapping to the same Site id as the first domain.

But I don’t know how this works exactly. Is it like a 301 redirect?

I should add that in the future i would like to use the second site to direct the visitor to the right website by country. Using a script like: redirect visitors by country/