Setting up a site on a new host and would like to keep the old site live on the previous host during the new build.

The new host allows a preview DNS feature where you can access the new site at mydomain.com.previewdns.com - this works for viewing and basic navigation.

The problem is that DNN page updates/changes want to send to the page at the original mydomain.com address, causing a 404 error every time a page or settings are updated.

I've been told the portal alias feature is where this situation might be resolved, but I can't seem to come up with the right combination of settings there to make it work.

I've added mydomain.com.previewdns.com as a portal alias, even set it to the default, but the problem persists.

Any suggestions on how to correct this issue? Are there specific settings I need to choose to make this work? Is the portal alias feature even the correct one for this case?

Is there any chance that you have some hard coded links that redirect you to the wrong site?

Nope - this is all happening when (for example) updating page settings. I can select a page, change the permissions, click update, and it sends me back to mydomain.com/pagename instead of mydomain.com.previewdns.com/pagename.

This of course, results in a 404. The permissions change will still take effect, but it never redirects to the correct page after an update.

Are there any entries in the PortalAlias table that refer to the other site? If there are, remove them.

Are you, by any chance, using a URL rewriter that could be doing this?

It shows mydomain.com.previewdns.com as the "default alias" in the dropdown, but I can't get rid of mydomain.com from the list, even if it's not set to default.

Mapping mode was canonical. I tried setting it to redirect. Now I can't get to any pages at all, no matter what I do, and cannot change it back. I'm hoping I don't need to reinstall now.

If mydomain.com appears in the list of portal aliases, you will need to get rid of it.

If you can't do this via the Admin Site Settings interface, you can always use the Host SQL page to delete entries from the PortalAlias table. You will then need to clear the cache and restart the application (both of these on the Host Settings page).

Reinstalling isn't necessary. Just fix the PortalAlias table and all should work fine.

I don't currently have any way to access any pages of the DNN install after switching that portal alias setting from canonical to redirect. Is there some other way to access this content to hopefully undo it?

Is there any way of letting me look at the site? You can write to me privately using the contact page at patapscorg.com.

After you get back into your site, I have a recommendation for working on your new site. You can change your hosts file on your computer to point the live site to the new preview site - for you only. the new entry would look something like this:

MyDomain.com mydomain.com.previewdns.com

Then, whenever your new dnn site tries to redirect to the old site, it will instead be pointed to the new site - just for you.

You will have to remember that you made this change to your hosts file and later comment it back out. Because you will not be able to actually get to the old site while this entry is there. - Good Luck