iDRAC login loop
Solution 1:
Have you tried looking at the iDRAC6 troubleshooting guide? They have a whole section of things to try for logon loops
Continual Loop
(Normally noticed when customer is trying to log into GUI Page).
Ensure customer is using a supported Browser
If customer has changed browser settings, reset to defaults and check.
Clear the browser cache and browser cookies and restart the browser.
Check the security settings of browser and the host operating system. Check the firewall settings to verify firewall is not blocking iDRAC network traffic
Reset iDRAC
Update FW/SW
Try draining flea power by unplugging the server from power source and then holding power button down for 20 seconds
Do an iDRAC reset to default using any of the following:
a) racadm racresetcfg (No host reboot required)
b) During POST enter CTRL+E option and execute Reset to default (Host reboot is required )
After reset to default is completed, reconfigure iDRAC settings (LAN config, IPMI over LAN etc.)
Replace parts
I've gotten these login loops before and usually the first 4 steps are enough to get me connected normally again. Usually, (assuming you haven't made changes to your browser) I start on step 3 and clear cache/cookies and can connect again about 90% of the time.
Solution 2:
I had this same problem on Firefox on Linux with iDrac6 after a FW upgrade to v2.90. It worked in Incognito mode but in normal mode kept looping back to the login screen. Clearing the web cache (not cookies) resolved the issue for me.