The forum software worked okay with this, and depending on which domain you used, set an appropriate cookie and off you went. All fine and dandy.
When I migrated to IPB 3.1.2 I found that it didn't work this way. You set your site URL and it is used throughout the templates etc. restricting you to just a single domain.
So ... after all that waffle ... my question is: Does xenForo support multiple domains for a single forum instance/install?