Can't access login after move to a new server

I am getting ready to move a WP site to a new server within our University. I was provided with a “staging site” to set it up and test. I installed WP on the staging site, and then used a back up from my current site to populate it. The site looks like everything is there- all of the content, but I have 2 problems. I can not access the Admin pages. The test server is stage.site.aaa.aaa, and the currently running site is site.aaa.aaa. When I try and access the WP-Admin, it redirects to the current site.

What do I need to fix to get this to work?

THX,