The Difference Between NTLM and Kerberos?

Is NTLM the same as Windows authentication?

I've just been learning about ASP.Net authentication and when I started reading up on how it works it was a bit confusing for me. Specifically the following text seems to contradict what I'd come to learn previously:

If you are developing applications that rely on Windows. Authentication with the default membership schema. settings, then we recommend that you read the security overview. first, so that you can ensure you use the correct authentication. scheme and membership provider. For example, you might use ASP.NET
Forms Authentication if your application is not dependent on users. roaming between networked computers. Is it correct to assume that NTLM and Windows authentication are different, if so what are the differences? Why does the book say one thing, but this answer says another? And vice versa? Is one better? How do these work exactly? And do these types of authentication have any drawbacks other than some performance hit? As far as I understand, from the Microsoft sources for ADAL/WCF, there is no difference between NTLM and Windows Auth. It's just that ADAL calls them both "Windows auth" internally.

You can also call it, "Windows (Lm & Nt)". But that doesn't matter, because NTLM is part of the base windows authentication mechanism. Windows authentication works in an entirely different way, and even if you don't use AD, it's still a completely different way of authentication.

I suggest to look at this msdn article about user accounts, where NTLM is explained: The Kerberos Security Provider. class provides the ability to. generate authentication information. This information is then used by. either ASP.NET's built-in Windows Forms authentication, or any custom. authentication method. When authenticating users, ASP.NET performs two steps: The first step. verifies the user's identity using a. domain controller. A unique account SID value for each user is associated. with each user's account name. The second step verifies the identity. of the user.

How do I check my NTLM authentication?

This is a discussion on ? within the Windows Programming forums, part of the Platform SDK category; How do I check if my NTLM authentication is set up correctly? My web application needs to authenticate to . My web application needs to authenticate to a website and I have been provided with a username/password combination. Unfortunately, I am having trouble using this information to authenticate in C#. Is there a way to check if my NTLM authentication is set up correctly? Thanks.
"It is a good plan to build your house before you move into it." -Benjamin Franklin. Re: How do I check my NTLM authentication? You can check it by querying the Authentication Header from your request. If you have NTLM authentication, the Authentication field will have the NTLM realm value in it (the domain name of the website). If the value is blank, then it's clear that you're not using NTLM.

Note: If you are authenticating to a website via the Internet Explorer (not the local machine), the NTLM authentication header should already be set. If it is not, then the website is blocking access from your machine."

This is interesting, but I still have a couple more questions. Does this mean that if I log in to my website and there's no authentication information in the request header, I'm using NTLM? If so, is there a way to change the default authentication mechanism from NTLM to Kerberos? I'd rather use Kerberos over NTLM because it seems to be the better method of authentication.

Originally posted by jayfel: I'm trying to use NTLM to authenticate to a website. It seems to work fine for the most part.

Is NTLM still secure?

I work on a LAN, on which there are 2 windows domain controllers. Both of them are on version 10 and NTLM authentication is enabled. I do not use any firewalls. The domain controller is configured to accept connections from the server's internal IP and its own IP as well. (The IPs are not static so I added these at setup). On Windows 7 I used to successfully login to both DC using my laptop. The other day I upgraded to Windows 8, installed the AD tools on my Windows 7 machine and connected to the DC using this machine. However I am having problems connecting. I had thought that the problem was due to the fact that the NTLM hash may not have been working correctly since the server is now a Windows 8 and was not sure if that's the case. So I removed the hashes on the server (as well as client) and tried to login to it using my Windows 7 machine and I'm still getting prompted for the password. As per Microsoft documentation:

When an account is enabled for LM and NTLM security, a user might be able to authenticate by using either of these logins, or both. If LM authentication is in use, but NTLM authentication is not, the NTLM protocol uses the NTLM message type to authenticate. This means that, after a user has authenticated successfully by using LM, the server can use the NTLM message to continue the authentication process.

So I'm not sure what to do about it. Any help would be appreciated.

Yes, there is absolutely a need for a "password change" option.but it doesn't even ask you for your current password anymore. A lot of people (not just you, from your other post) are finding that their users don't want to enter new passwords, so they're locking out legitimate users.

Also, did you go to the Users tab, and look for accounts you no longer have access to, then delete them? Thanks.