Why the authentication was NTLM and not Kerberos?

Why the authentication was NTLM and not Kerberos?

The main difference between NTLM and Kerberos is in how the two protocols manage authentication. NTLM relies on a three-way handshake between the client and server to authenticate a user. Kerberos uses a two-part process that leverages a ticket granting service or key distribution center.

Why does Kerberos fail authentication?

This problem can occur when a domain controller doesn’t have a certificate installed for smart card authentication (for example, with a “Domain Controller” or “Domain Controller Authentication” template), the user’s password has expired, or the wrong password was provided.

How do I fix Kerberos authentication error?

Resolution. To resolve this problem, update the registry on each computer that participates in the Kerberos authentication process, including the client computers. We recommend that you update all of your Windows-based systems, especially if your users have to log on across multiple domains or forests.

Is NTLM better than Kerberos?

Kerberos provides several advantages over NTLM: – More secure: No password stored locally or sent over the net. – Best performance: improved performance over NTLM authentication. – Delegation support: Servers can impersonate clients and use the client’s security context to access a resource.

How do you tell if you are using Kerberos or NTLM?

Once Kerberos logging is enabled, then, log into stuff and watch the event log. If you’re using Kerberos, then you’ll see the activity in the event log. If you are passing your credentials and you don’t see any Kerberos activity in the event log, then you’re using NTLM.

Why is NTLM not secure?

Is NTLM secure? NTLM is generally considered insecure because it uses outdated cryptography that is vulnerable to several modes of attacks. NTLM is also vulnerable to the pass-the-hash attack and brute-force attacks.

Do you not need Kerberos preauthorization?

When you do not enforce pre-authentication, a malicious attacker can directly send a dummy request for authentication. The KDC will return an encrypted TGT and the attacker can brute force it offline.

What is Kerberos authentication protocol?

Kerberos is a computer network security protocol that authenticates service requests between two or more trusted hosts across an untrusted network, like the internet. It uses secret-key cryptography and a trusted third party for authenticating client-server applications and verifying users’ identities.

How do I troubleshoot NTLM authentication?


  1. Ensure that NetBIOS Name Resolution is enabled on the Domain Controller to which the Web Gateway is sending the NTLM requests.
  2. Ensure that NTLM 401 Authentication is allowed on the Domain Controller.
  3. Check the LDAP Authentication.
  4. Check the NTLM settings.
  5. Check the client browser settings.
  6. Check the DNS settings.

What does Ntlm mean?

NT (New Technology) LAN Manager
In a Windows network, NT (New Technology) LAN Manager (NTLM) is a suite of Microsoft security protocols intended to provide authentication, integrity, and confidentiality to users. NTLM is the successor to the authentication protocol in Microsoft LAN Manager (LANMAN), an older Microsoft product.

How do I switch from NTLM to Kerberos?

From home of the SharePoint:

  1. On the left, click on Security.
  2. On the right, click on Specify authentication providers.
  3. Click on Default.
  4. There you will find it then change the authentication from NTLM to kerberos and vise versa.

Why is Kerberos more secure than NTLM?

Security. – While both the authentication protocols are secure, NTLM is not as secure as Kerberos because it requires a point-to-point connection between the Web browser and server in order to function properly. Kerberos is more secure because it never transmits passwords over the network in the clear.

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