[NAME]-R, This is an issue with iDRAC firmware 2.75.100.75. Next iDRAC firmware release will have fix for this. Mean time you can launch iDRAC directly with "https:// /login.html" or "https:// /start.html". 
In the latest 13G iDRAC firmware, 2.75.100.75, the initial web UI login now redirects to its IP address, rather than the provided Host header. old (up to 2.75.75.75) The document has moved here. (We don't really use fruit-based names, but this is just to show how the redirect URL is constructed.) new (2.75.100.75) The document has moved here. Note the IP address in the destination URL. With trusted SSL certificates, this causes a security prompt. As there's nothing in the Fixes & Enhancements notes about this, and it seems somewhat strange, can anyone explain what we're seeing?
iDRAC 2.75.100.75 13G HTTP redirect