Symptoms

After a clean installation of K2, the Designer load successfully in Chrome with errors in IE with the following:

Multiple authentication attempts detected
Detected an instance where Relying Trust is not configured properly, and requesting tokens repeatedly. Please ensure that the link to the K2 Server is added to the browser's trusted sites.
 

Diagnoses

It was determined that this was due to an IE issue of not being able to resolve hostnames w/ underscores '_'. I.e.

http://dev_server:80/designer

Similarly to the resources below:

http://blog.smartbear.com/software-quality/internet-explorer-eats-cookies-with-underscores-in-the-hostname/

https://connect.microsoft.com/IE/feedback/details/853796/internet-explorer-wont-save-cookies-on-domains-with-underscores-in-them
 

Resolution

Some possible resolutions taken from the post (http://blog.smartbear.com/software-quality/internet-explorer-eats-cookies-with-underscores-in-the-hostname/) includes perhaps:

1. Using a different browser such as Chrome/Firefox/Safari as it is not affected

2. Renaming the server machine (or using DNS alias), and re-configuring all K2 components to recognize/reflect these changes (preferred option)

3. Use .hosts files to simulate a DNS alias