Chapter 3. Setting up Samba on an IdM domain member

Procedure

1. Install the required packages:

   [root@ipaserver ~]# dnf install ipa-server-trust-ad samba-client

2. Authenticate as the IdM administrative user:

   [root@ipaserver ~]# kinit admin

3. Run the ipa-adtrust-install utility:

   [root@ipaserver ~]# ipa-adtrust-install

   The DNS service records are created automatically if IdM was installed with an integrated DNS server.

   If you installed IdM without an integrated DNS server, ipa-adtrust-install prints a list of service records that you must manually add to DNS before you can continue.

4. The script prompts you that the /etc/samba/smb.conf already exists and will be rewritten:

   WARNING: The smb.conf already exists. Running ipa-adtrust-install will break your existing Samba configuration.
   
   Do you wish to continue? [no]: yes

5. The script prompts you to configure the slapi-nis plug-in, a compatibility plug-in that allows older Linux clients to work with trusted users:

   Do you want to enable support for trusted domains in Schema Compatibility plugin?
   This will allow clients older than SSSD 1.9 and non-Linux clients to work with trusted users.
   
   Enable trusted domains support in slapi-nis? [no]: yes

6. You are prompted to run the SID generation task to create a SID for any existing users:

   Do you want to run the ipa-sidgen task? [no]: yes

   This is a resource-intensive task, so if you have a high number of users, you can run this at another time.

7. Optional: By default, the Dynamic RPC port range is defined as 49152-65535 for Windows Server 2008 and later. If you need to define a different Dynamic RPC port range for your environment, configure Samba to use different ports and open those ports in your firewall settings. The following example sets the port range to 55000-65000.

   [root@ipaserver ~]# net conf setparm global 'rpc server dynamic port range' 55000-65000
   [root@ipaserver ~]# firewall-cmd --add-port=55000-65000/tcp
   [root@ipaserver ~]# firewall-cmd --runtime-to-permanent

8. Restart the ipa service:

   [root@ipaserver ~]# ipactl restart

9. Use the smbclient utility to verify that Samba responds to Kerberos authentication from the IdM side:

   [root@ipaserver ~]# smbclient -L ipaserver.idm.example.com -U user_name --use-kerberos=required
   lp_load_ex: changing to config backend registry
       Sharename       Type      Comment
       ---------       ----      -------
       IPC$            IPC       IPC Service (Samba 4.15.2)
   ...

Procedure

1. Install the ipa-client-samba package:

   [root@idm_client]# dnf install ipa-client-samba

2. Use the ipa-client-samba utility to prepare the client and create an initial Samba configuration:

   [root@idm_client]# ipa-client-samba
   Searching for IPA server...
   IPA server: DNS discovery
   Chosen IPA master: idm_server.idm.example.com
   SMB principal to be created: cifs/idm_client.idm.example.com@IDM.EXAMPLE.COM
   NetBIOS name to be used: IDM_CLIENT
   Discovered domains to use:
   
    Domain name: idm.example.com
   NetBIOS name: IDM
            SID: S-1-5-21-525930803-952335037-206501584
       ID range: 212000000 - 212199999
   
    Domain name: ad.example.com
   NetBIOS name: AD
            SID: None
       ID range: 1918400000 - 1918599999
   
   Continue to configure the system with these values? [no]: yes
   Samba domain member is configured. Please check configuration at /etc/samba/smb.conf and start smb and winbind services

3. By default, ipa-client-samba automatically adds the [homes] section to the /etc/samba/smb.conf file that dynamically shares a user’s home directory when the user connects. If users do not have home directories on this server, or if you do not want to share them, remove the following lines from /etc/samba/smb.conf:

   [homes]
       read only = no

4. Share directories and printers. For details, see the following sections:

   • Setting up a Samba file share that uses POSIX ACLs
   • Setting up a share that uses Windows ACLs
   • Setting up Samba as a print server

5. Open the ports required for a Samba client in the local firewall:

   [root@idm_client]# firewall-cmd --permanent --add-service=samba-client
   [root@idm_client]# firewall-cmd --reload

6. Enable and start the smb and winbind services:

   [root@idm_client]# systemctl enable --now smb winbind

Procedure

1. Authenticate using the host’s keytab:

   [root@idm_client]# kinit -k

2. Use the ipa idrange-find command to display both the base ID and the ID range size of the new domain. For example, the following command displays the values for the ad.example.com domain:

   [root@idm_client]# ipa idrange-find --name="AD.EXAMPLE.COM_id_range" --raw
   ---------------
   1 range matched
   ---------------
     cn: AD.EXAMPLE.COM_id_range
     ipabaseid: 1918400000
     ipaidrangesize: 200000
     ipabaserid: 0
     ipanttrusteddomainsid: S-1-5-21-968346183-862388825-1738313271
     iparangetype: ipa-ad-trust
   ----------------------------
   Number of entries returned 1
   ----------------------------

   You need the values from the ipabaseid and ipaidrangesize attributes in the next steps.

3. To calculate the highest usable ID, use the following formula:

   maximum_range = ipabaseid + ipaidrangesize - 1

   With the values from the previous step, the highest usable ID for the ad.example.com domain is 1918599999 (1918400000 + 200000 - 1).

4. Edit the /etc/samba/smb.conf file, and add the ID mapping configuration for the domain to the [global] section:

   idmap config AD : range = 1918400000 - 1918599999
   idmap config AD : backend = sss

   Specify the value from ipabaseid attribute as the lowest and the computed value from the previous step as the highest value of the range.

5. Restart the smb and winbind services:

   [root@idm_client]# systemctl restart smb winbind