400 Bad Request errors seen after updating our series 5 iDRACs to version 2.83.83.83

[marcsjohnson]

Heads-up... 

After updating our series 5 iDRACS at our older site to version 2.83.83.83, all my browsers got '400 Bad Request' errors and wouldn't render our iDRAC GUIs using our DNS alias names.   I had to use the direct IPs on the browser's URL address field to login to our iDRACs. 

I rolled back to iDRAC version 2.70.70.70 and that resolved the issue.  

[VincentWareham]

Hello marcsjohnson

Please see the following Dell Community Discussion which mentions that firmware 2.83.83.83 enforces HTTP or HTTPS Host Header check by default, which can result in "Access Error: 400 -- Bad Request".

Reference: Upgraded idrac8 firmware from 2.70.70.70 to 2.83.83.83 and cant no longer use FQDN to access idrac

It includes suggestions to resolve.