Service Bus UnauthorizedAccessException token provider was unable to provide a security token while accessing custom STS

I installed the service bus for windows server on my windows server 2012. Then I setuped the new service bus farm and followed the tutorial on MSDN to test the brokered message queue client.

However, I am getting the error as below.

This error can not provide a security token for the user I setup run as from sb farm, which username@domain.

After some test, I realized the issue is caused by the run as user has to be given a full userdnsdomain name. So when you set up the service bus farm, make sure it is uisng username@domain.com format.

Then it worked as expected.