Portal aliases are used to ensure consistent branding of your site.  For example, you may want to own MySite.com, MySite.Net, ThisIsMySite.biz, etc.  However, you want your site to only be known by MySite.com.  So, if you setup MySite.com as a portal alias, all of the other requests that point to your site will be redirected to the "allowed" portal alias.

In general, you should setup one preferred alias for your public-facing site, and you will probably also have an alias or two for locahost situations, where you don't want to be redirected to the main URL.  Each URL that needs access to the site needs a portal alias, if a URL hits your site that isn't setup as an alias, it will redirected to your main (first) alias.

Hope that helps,

Hey Guys,

I'd chime in and say that you are both right, and that I would first think of yet a third use portal aliases.

Brian's scenario: Set up ten domain names to point to my server. Set up my web site in IIS to handle all of those domains and direct them to my DNN site (host headers probably).  Only add the "main" URL to your list of portal aliases. When you go to any URL that's not in the list of protal aliases, but your website is responsible for handling - - you'll go to the primary URL. This is probably not the best way to perform this kind of thing though. It's probably easier just to set up different web sites in IIS and perform real permanent redirects.

Jeff's scenario is so that you can access the same website from different locations. This is frequently the "Developer" scenario - i want to pull down a database from production and put it on my development machine and access it from a different URL -- add a portal alias and you're good to go.

A third scenario would be that I would add is to have www.mysite.com be portal 0 and http://ian.mysite.com be portal 1 and jeff.mysite.com be portal 2, etc... If you have DNS and IIS configured properly, all you have to do is add a portal alias to get that functionality.

Hope that helps,

Ian