If you are using Kerberos, verify that your environment meets the requirements listed in the following table before you configure the driver for Kerberos authentication.

Table 1. Kerberos Authentication Requirements for the SQL Server Wire Protocol Driver
Component Requirements
Database server The database server must be administered by the same domain controller that administers the client.
Kerberos server The Kerberos server is the machine where the user IDs for authentication are administered. The Kerberos server is also the location of the Kerberos KDC. Network authentication must be provided by Microsoft Entra Kerberos.
Client The client must be administered by the same domain controller that administers the database server.

Kerberos authentication can take advantage of the user name and password maintained by the operating system to authenticate users to the database or use another set of user credentials specified by the application.

The Kerberos method requires knowledge of how to configure your Kerberos environment. This method supports both Microsoft Entra Kerberos and MIT Kerberos environments.

To use Kerberos authentication, the application user first must obtain a Kerberos Ticket Granting Ticket (TGT) from the Kerberos server. The Kerberos server verifies the identity of the user and controls access to services using the credentials contained in the TGT.

If the application uses Kerberos authentication from a UNIX/Linux client, the user must explicitly obtain a TGT. To obtain a TGT explicitly, the user must log onto the Kerberos server using the kinit command. For example, the following command requests a TGT from the server with a lifetime of 10 hours, which is renewable for 5 days: 

kinit -l 10h -r 5d user

where user is the application user.

Refer to your Kerberos documentation for more information about using the kinit command and obtaining TGTs for users.

If the application uses Kerberos authentication from a Windows client, the application user does not explicitly need to obtain a TGT. Microsoft Entra Kerberos automatically obtains a TGT for the user.