i created a parent portal called portal2.mywebsite.com. but when i try to browse this URL nothing comes up.  do I need to add an A record for this?  If so, how will DNN know which portal to redirect to. 

Are there limitations to this in a shared hosting environment?  does the parent portal need a second DB?  is there a doc that spells all this out?

v4.5.3

Just make sure that any new domains are pointed at the same place.. the root of your DNN instance. Also make sure they have been individually enabled as ASP.Net 2 applications.

Add your new portal as a child portal and that way you can see it working by browsing the first domain/childportal. When it has successfully opened, log into it and add your new domain as a portal alias in the site settings. now try browsing via the new domain. The only difference between a parent and child is the latter has an extra folder in the root of the parent portal that handles the http://domain/child URL, so to be certain it works at all, create a child first.

There is only the one db and performance aside, shared hosting is no problem. However, your host must allow you to add more than one domain to the same folder. This is often not made clear until you try it out and find you either have to pay extra or upgrade the account. If you're on Webshost4life they will ask you for $15 per year for an additional domain (with email service) above the number that are included in your package. That might be anywhere from 1 to 10 or more.

As for your specific scenario of http://name.domain - I haven't used that type of domain yet here and it might be a lttle different. You may be able to have a second portal using such a name is you point it to the subdirectory where the child portal homepage resides. So I suggest setting up a child first and then see if you can direct it to that folder. Let me know if that works as I'd like to do the same at some point.

Hope that helps

Rob