We have Exchange 2013 and have added IP address restrictions to the ecp application in IIS.
While it works it has its quirks...
For starters if I log in via a whitelisted IP I initially get the 403.503 Forbidden page but if I refresh the browser page I get a bit more of the ecp proper, then refresh a second time and the site appears and functions normally.
Does anyone know why this might be the case?
Also I note that when browsing to /ecp it initially redirects to /owa/auth... etc for the login page. It even does this when browsing from a restricted IP. From a restricted IP when typing in a correct credential it simply takes you back to the login page and doesn't log you in.
So it appears that the redirection from /ecp to /owa/auth occurs before IP restrictions are enforced. Is there a way around this?