If an invalid user tries to authentication to a domain, is there a fix time it takes to return with an error or depends on how many users there are in the domain? The response with wrong password is quick but wrong user name takes much longer. Does it take longer and longer to respond for invalid users to counter DoS attacks?

Hi, After viewing the question, I think it is better to ask in Windows Server Forum to get professional answer. Win Server Forum http://social.technet.microsoft.com/Forums/en-US/category/windowsserver If you have any question regarding Windows 7, I am glad to be your assistance. Best Regards, Niki Please remember to click "Mark as Answer" on the post that helps you, and to click "Unmark as Answer" if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.