Set Up Kerberos Authentication

Kerberos is a computer network authentication protocol that works on the basis of tickets to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner.
  1. Create a server profile.
    The server profile identifies the external authentication service and instructs the firewall how to connect to that authentication service and access the authentication credentials for your users.
    1. Select DeviceServer Profiles and select the Kerberos profile.
    2. Click Add and enter a Profile Name, such as GP-User-Auth.
    3. If this profile is for a firewall with multiple virtual systems capability, select a virtual system or Shared as the Location where the profile is available.
    4. Click Add in the Servers section and then enter the necessary information for connecting to the authentication server, including the server Name, IP address or FQDN of the Server, and Port.
    5. Click OK to save the server profile.
  2. (Optional) Create an authentication profile.
    The authentication profile specifies the server profile for the portal or gateways to use when they authenticate users. On a portal or gateway, you can assign one or more authentication profiles in one or more client authentication profiles. For descriptions of how an authentication profile within a client authentication profile supports granular user authentication, see Configure a GlobalProtect Gateway and Set Up Access to the GlobalProtect Portal.
    To enable users to connect and change their own expired passwords without administrative intervention, consider using a pre-logon connect method. See Remote Access VPN with Pre-Logon for details.
    1. Select DeviceAuthentication Profile and Add a new profile.
    2. Enter a Name for the profile and then select Kerberos as the authentication Type.
    3. Select the Kerberos authentication Server Profile that you created in 1 from the drop-down.
    4. Specify the domain name and username format. The device combines the User Domain and Username Modifier values to modify the domain/username string that a user enters during login. The device uses the modified string for authentication and uses the User Domain value for User-ID group mapping. Modifying user input is useful when the authentication service requires domain/username strings in a particular format and you don’t want to rely on users to correctly enter the domain. You can select from the following options:
      • To send only the unmodified user input, leave the User Domain blank (the default) and set the Username Modifier to the variable %USERINPUT% (the default).
      • To prepend a domain to the user input, enter a User Domain and set the Username Modifier to %USERDOMAIN%\%USERINPUT%.
      • To append a domain to the user input, enter a User Domain and set the Username Modifier to %USERINPUT%@%USERDOMAIN%.
      If the Username Modifier includes the %USERDOMAIN% variable, the User Domain value replaces any domain string that the user enters. If the User Domain is blank, that means the device removes any user-entered domain string.
    5. Configure Kerberos single sign-on (SSO) if your network supports it:
      • Enter the Kerberos Realm (up to 127 characters). This is the hostname portion of the user login name. For example, the user account name user@EXAMPLE.LOCAL has the realm EXAMPLE.LOCAL.
      • Specify a Kerberos Keytab file: click the Import link, Browse to the keytab file, and click OK. During authentication, the endpoint first tries to use the keytab to establish SSO. If it succeeds, and the user attempting access is in the Allow List, authentication succeeds immediately. Otherwise, the authentication process falls back to manual (username/password) authentication of the specified Type. The Type doesn’t have to be Kerberos. To change this behavior so that users can authenticate only using Kerberos, set Use Default Authentication on Kerberos Authentication Failure to No in a GlobalProtect portal agent configuration.
    6. Select the Advanced tab.
    7. In the Allow List, Add and then select the users and groups that are allowed to authenticate with this profile. Selecting the predefined all option allows every user to authenticate. By default, the list has no entries, which means no users can authenticate.
  3. Save your changes and commit the configuration.
    Click OK, and then Commit.

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