3.4. Manually adding an ID mapping configuration if IdM trusts a new domain
Samba requires an ID mapping configuration for each domain from which users access resources. On an existing Samba server running on an IdM client, you must manually add an ID mapping configuration after the administrator added a new trust to an Active Directory (AD) domain.
Prerequisites
- You configured Samba on an IdM client. Afterward, a new trust was added to IdM.
- The DES and RC4 encryption types for Kerberos must be disabled in the trusted AD domain. For security reasons, RHEL 10 does not support these weak encryption types.
Procedure
Authenticate using the host’s keytab:
[root@idm_client]# kinit -kUse the
ipa idrange-findcommand to display both the base ID and the ID range size of the new domain. For example, the following command displays the values for thead.example.comdomain:[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
ipabaseidandipaidrangesizeattributes in the next steps.To calculate the highest usable ID, use the following formula:
maximum_range = ipabaseid + ipaidrangesize - 1With the values from the previous step, the highest usable ID for the
ad.example.comdomain is1918599999(1918400000 + 200000 - 1).Edit the
/etc/samba/smb.conffile, and add the ID mapping configuration for the domain to the[global]section:idmap config AD : range = 1918400000 - 1918599999 idmap config AD : backend = sssSpecify the value from
ipabaseidattribute as the lowest and the computed value from the previous step as the highest value of the range.Restart the
smbandwinbindservices:[root@idm_client]# systemctl restart smb winbind
Verification
List the shares on the Samba server using Kerberos authentication:
$ smbclient -L idm_client.idm.example.com -U user_name --use-kerberos=required lp_load_ex: changing to config backend registry Sharename Type Comment --------- ---- ------- example Disk IPC$ IPC IPC Service (Samba 4.15.2) ...