Merge pull request #3645 from meet-bhagdev/patch-61

Update sql-server-linux-active-directory-authentication.md

Author: PRMerger17

docs/linux/sql-server-linux-active-directory-authentication.md

@@ -138,8 +138,13 @@ Use the following steps to join a [!INCLUDE[ssNoVersion](../includes/ssnoversion
    > If you see an error, "Necessary packages are not installed," then you should install those packages using your Linux distribution's package manager before running the `realm join` command again.
    >
    > If you receive an error, "Insufficient permissions to join the domain," then you will need to check with a domain administrator that you have sufficient permissions to join Linux machines to your domain.
+   
+   > SQL Server uses SSSD and NSS for mapping user accounts and groups to security identifiers (SID's). SSSD must be configured and running in order for SQL Server to create AD logins successfully. Realmd will usually do this automatically as part of joining the domain, but in some cases you will need to do this separately.
+   >
+   > Check out the following to configure [SSSD manually](https://access.redhat.com/articles/3023951), and [configure NSS to work with SSSD](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system-level_authentication_guide/configuring_services#Configuration_Options-NSS_Configuration_Options)
 
-1. Verify that you can now gather information about a user from the domain, and that you can acquire a Kerberos ticket as that user.
+  
+5. Verify that you can now gather information about a user from the domain, and that you can acquire a Kerberos ticket as that user.
 
    We will use **id**, **[kinit](https://web.mit.edu/kerberos/krb5-1.12/doc/user/user_commands/kinit.html)** and **[klist](https://web.mit.edu/kerberos/krb5-1.12/doc/user/user_commands/klist.html)** commands for this.