With older versions of Internet Explorer, specifically IE6 on Windows XP, cookies are never accepted from localhost. This includes 127.0.0.1, the ip address assigned to the host, as well as names that resolve to either of the above.
Most versions of Internet Explorer refuse to accept cookies from hosts that contain underscores in their name, such as Splunk_server
In order to login into Splunk Web successfully, the following are required:
The browser must have cookies enabled. The browser must be able to download cookies.
The client machine and the server on which Splunk is running on must be at least on the same GMT time. IE browser has a higher security enabled that it verifies the downloaded cookie timestamp with the server and client. If they are off, user will loop at login page and not be able to login.
Timezone difference is fine, as long as in relation to GMT time, is the same. For example,
if the Splunk server is at EST and the client is at PST time, there is a difference of 3 hours, but according to GMT, EST is always 3 hours behind, and PST is always 6 hours behind. Hence, according to GMT time both client and server are on same time so this works.
IE by default has added security checking enabled that results in such behavior, whereas on Firefox you don't.