I just set the dotnetnuke to use domain name(domain name point to IP Address/Virtual Directory and add the domain name to portal alias). The problem is under the domain name, user cannot login using internet explorer with medium privacy (must set it to low) but if using ipaddress, user can login using medium privacy. Is there any setting to make user can login using medium privacy under the domain name?

Also if I hover cursor over all the link in the portal now is showing the IP address (Basically the url not change when navigate through the pages just pointing to domain name). Is there anyway to fix this?