www. not working for new domains

I’m using the domains plugins to allow domain name to be setup for each mu site if you type in the dname like so foo.com it works but if you try to do https://www.foo.com it errors out saying that it cant find it…

I went in to each domain name and set up the @ to the ip of the server and the www. to the same ip address as a A-type forwarder.. but it just doesnt work.

should i setup the www. to just do a dname forward to the non-www domain ?