How do I force the FQDN,, with a standard Vibe install?

We have users that use http://server and others that use

This causes a user to have to re-authenticate when a link is sent using the other method that they are currently logged in as.

example: I am logged into vibe using and get sent a link from another use that is logged in using http://server. When I click the link I have to login again; and vice-versa if I were send a link back.