Chapter 34. Installing trust between IdM and AD Learn more about how to create a trust between the Identity Management IdM server and Active Directory (AD), where both servers are located in the same forest. Note In RHEL 7, synchronization and trust were two possible approaches to indirect integration of RHEL systems to Active Directory (AD). In RHEL 8, synchronization is deprecated. To integrate IdM and AD, use the trust approach instead. To migrate from synchronization to trust, see Migrating an existing environment from synchronization to trust in the context of integrating a Linux domain with an Active Directory domain . Prerequisites First, read the Planning a cross-forest trust between Identity Management and Active Directory document. AD is installed with a domain controller on it. The IdM server is installed and running. For details, see Installing Identity Management . Both the AD server and the IdM server must have their clocks in sync because Kerberos requires max 5 mins delay in communication. Unique NetBIOS names for each of the servers placed in the trust because the NetBIOS names are critical for identifying the Active Directory domain. The NetBIOS name of an Active Directory or IdM domain is usually the first part of the corresponding DNS domain. If the DNS domain is ad.example.com , the NetBIOS name is typically AD . However, it is not required. Important is that the NetBIOS name is just one word without periods. The maximum length of a NetBIOS name is 15 characters. The IdM system must have the IPv6 protocol enabled in the kernel. If IPv6 is disabled, then the CLDAP plug-in used by the IdM services fails to initialize. 34.1. Supported versions of Windows Server You can establish a trust relationship with Active Directory (AD) forests that use the following forest and domain functional levels: Forest functional level range: Windows Server 2012 - Windows Server 2016 Domain functional level range: Windows Server 2012 - Windows Server 2016 Identity Management (IdM) supports establishing a trust with Active Directory domain controllers running the following operating systems: Windows Server 2022 (RHEL 8.7 and later) Windows Server 2019 Windows Server 2016 Windows Server 2012 R2 Windows Server 2012 Important In RHEL 8.4, Identity Management (IdM) does not support establishing trust to Active Directory with Active Directory domain controllers running Windows Server 2008 R2 or earlier versions. RHEL IdM now requires SMB encryption when establishing the trust relationship, which is only supported in Windows Server 2012 or later. 34.2. How the trust between IdM and AD works The trust between Identity Management (IdM) and Active Directory (AD) is established on the cross-realm Kerberos trust. This solution uses the Kerberos capability to establish trusts between different identity sources. Therefore, all AD users can: Log in to access Linux systems and resources. Use single sign-on (SSO). In the trust relationship, all IdM objects are managed in IdM, while all AD objects are managed in AD. In complex environments, a single IdM forest can be connected to multiple AD forests. This setup enables better separation of duties for different functions in the organization. AD administrators can focus on users and policies related to users while Linux administrators have full control over the Linux infrastructure. In such a case, the Linux realm controlled by IdM is analogous to an AD resource domain or realm but with Linux systems in it. From the perspective of AD, Identity Management represents a separate AD forest with a single AD domain. When cross-forest trust is established between an AD forest root domain and an IdM domain, users from the AD forest domains can interact with Linux machines and services from the IdM domain. Note In trust environments, IdM enables you to use ID views to configure POSIX attributes for AD users on the IdM server. 34.3. AD administration rights When you want to establish a trust between AD (Active Directory) and IdM (Identity Management), you must use an AD administrator account with appropriate AD privileges. The AD administrator must belong to one of the following groups: Enterprise Admin group in the AD forest Domain Admins group in the forest root domain for your AD forest Additional resources Enterprise Admins Domain Admins How Domain and Forest Trusts Work 34.4. Ensuring support for common encryption types in AD and RHEL By default, Identity Management establishes a cross-realm trust with support for AES-128 and AES-256 Kerberos encryption types. Additionally, by default SSSD and Samba Winbind support AES-128 and AES-256 Kerberos encryption types. RC4 encryption is deprecated and disabled by default since RHEL 8.3 and RHEL 9, as it is considered less secure than the newer AES-128 and AES-256 encryption types. In contrast, Active Directory (AD) user credentials and trusts between AD domains support RC4 encryption and they might not support all AES encryption types. Without any common encryption types, communication between RHEL hosts and AD domains might not work, or some AD accounts might not be able to authenticate. To address this situation, perform one of the configurations outlined in the following sections. Important If IdM is in FIPS mode, the IdM-AD integration does not work due to AD only supporting the use of RC4 or AES HMAC-SHA1 encryptions, while RHEL 9 in FIPS mode allows only AES HMAC-SHA2 by default. For more information, see the AD Domain Users unable to login in to the FIPS-compliant environment KCS solution. IdM does not support the more restrictive FIPS:OSPP crypto policy, which should only be used on Common Criteria evaluated systems. 34.4.1. Enabling AES encryption in AD (recommended) To ensure trusts between Active Directory (AD) domains in an AD forest support strong AES encryption types, see the following Microsoft article: AD DS: Security: Kerberos "Unsupported etype" error when accessing a resource in a trusted domain 34.4.2. Enabling the AES encryption type in Active Directory using a GPO Enable the AES encryption type in Active Directory (AD) using a group policy object (GPO). Certain features on RHEL, such as running a Samba server on an IdM client, require this encryption type. Note that RHEL no longer supports the weak DES and RC4 encryption types. Prerequisites You are logged into AD as a user who can edit group policies. The Group Policy Management Console is installed on the computer. Procedure Open the Group Policy Management Console. Right-click Default Domain Policy , and select Edit . The Group Policy Management Editor opens. Navigate to Computer Configuration Policies Windows Settings Security Settings Local Policies Security Options . Double-click the Network security: Configure encryption types allowed for Kerberos policy. Select AES256_HMAC_SHA1 and, optionally, Future encryption types . Click OK . Close the Group Policy Management Editor. Repeat the steps for the Default Domain Controller Policy . Wait until the Windows domain controllers (DC) applied the group policy automatically. Alternatively, to apply the GPO manually on a DC, enter the following command using an account that has administrator permissions: 34.4.3. Enabling RC4 support in RHEL On every RHEL host where authentication against AD Domain Controllers takes place, complete the steps outlined below. Procedure Use the update-crypto-policies command to enable the AD-SUPPORT cryptographic subpolicy in addition to the DEFAULT cryptographic policy. Restart the host. Important The AD-SUPPORT cryptographic subpolicy is only available on RHEL 8.3 and newer. To enable support for RC4 in RHEL 8.2, create and enable a custom cryptographic module policy with cipher = RC4-128+ . For more details, see Customizing system-wide cryptographic policies with subpolicies . To enable support for RC4 in RHEL 8.0 and RHEL 8.1, add +rc4 to the permitted_enctypes option in the /etc/crypto-policies/back-ends/krb5.config file: 34.4.4. Additional resources Using system-wide cryptographic policies Trust controllers and trust agents 34.5. Ports required for communication between IdM and AD To enable communication between your Active Directory (AD) and Identity Management (IdM) environments, open the following ports on the firewalls of your AD Domain Controllers and IdM servers. Table 34.1. Ports required for an AD trust Service Port Protocol Endpoint resolution portmapper 135 TCP NetBIOS-DGM 138 TCP and UDP NetBIOS-SSN 139 TCP and UDP Microsoft-DS 445 TCP and UDP Dynamic RPC 49152-65535 TCP AD Global Catalog 3268 TCP LDAP 389 TCP and UDP Note The TCP port 389 is not required to be open on IdM servers for trust, but it is necessary for clients communicating with the IdM server. The TCP port 135 is required for the DCE RPC end-point mapper to work and is used during the IdM-AD trust creation. To open ports, you can use the following methods: firewalld service - you can enable the particular ports or enable the following services which includes the ports: FreeIPA trust setup FreeIPA with LDAP Kerberos DNS For details, see the firewall-cmd man page on your system. Note If you are using RHEL 8.2 and earlier, the freeipa-trust firewalld service includes an RPC port range of 1024-1300 , which is incorrect. On RHEL 8.2 and earlier, you must manually open the TCP port range 49152-65535 in addition to enabling the freeipa-trust firewalld service. This issue has been fixed for RHEL 8.3 and later in Bug 1850418 - update freeipa-trust.xml definition to include correct dynamic RPC range . The RHEL web console, which is a UI with firewall settings based on the firewalld service. For details about firewall configuration through the web console, see Enabling services on the firewall using the web console Note If you are using RHEL 8.2 and earlier, the FreeIPA Trust Setup service includes an RPC port range of 1024-1300 , which is incorrect. On RHEL 8.2 and earlier, you must manually open the TCP port range 49152-65535 in addition to enabling the FreeIPA Trust Setup service in the RHEL web console. This issue has been fixed for RHEL 8.3 and later in Bug 1850418 - update freeipa-trust.xml definition to include correct dynamic RPC range . Table 34.2. Ports required by IdM servers in a trust Service Port Protocol Kerberos 88, 464 TCP and UDP LDAP 389 TCP DNS 53 TCP and UDP Table 34.3. Ports required by IdM clients in an AD trust Service Port Protocol Kerberos 88 UDP and TCP Note The libkrb5 library uses UDP and falls back to the TCP protocol if the data sent from the Key Distribution Center (KDC) is too large. Active Directory attaches a Privilege Attribute Certificate (PAC) to the Kerberos ticket, which increases the size and requires to use the TCP protocol. To avoid the fall-back and resending the request, SSSD uses TCP for user authentication by default. If you want to configure the size before libkrb5 uses TCP, set the udp_preference_limit in the /etc/krb5.conf file. For details, see the krb5.conf(5) man page on your system. The following diagram shows communication sent by IdM clients, and received and responded to by IdM servers and AD Domain Controllers. To set the incoming and outgoing ports and protocols on your firewall, use the firewalld service, which already has definitions for FreeIPA services. Additional resources The default dynamic port range for TCP/IP has changed since Windows Vista and in Windows Server 2008 34.6. Configuring DNS and realm settings for a trust Before you connect Identity Management (IdM) and Active Directory (AD) in a trust, ensure that servers see each other and resolve domain names correctly. To configure domain name resolution between: A primary IdM server using integrated DNS server and Certification Authority (CA) An AD Domain Controller Perform the following tasks: Configure DNS zones on the IdM server Configure conditional DNS forwarding on the AD server Verify correctness of the DNS configuration 34.6.1. Unique primary DNS domains In Windows, every domain is a Kerberos realm and a DNS domain at the same time. Every domain managed by the domain controller needs to have its own dedicated DNS zone. The same applies when Identity Management (IdM) is trusted by Active Directory (AD) as a forest. AD expects IdM to have its own DNS domain. For the trust setup to work, the DNS domain must be dedicated to the Linux environment. Each system must have its own unique primary DNS domain configured. For example: ad.example.com for AD and idm.example.com for IdM example.com for AD and idm.example.com for IdM ad.example.com for AD and example.com for IdM The most convenient management solution is an environment where each DNS domain is managed by integrated DNS servers, but it is possible to use any other standard-compliant DNS server as well. Kerberos realm names as upper-case versions of primary DNS domain names Kerberos realm names must match the primary DNS domain names, with all letters uppercase. For example, if the domain names are ad.example.com for AD and idm.example.com for IdM, the Kerberos realm names are required to be AD.EXAMPLE.COM and IDM.EXAMPLE.COM . DNS records resolvable from all DNS domains in the trust All machines must resolve DNS records from all DNS domains involved in the trust relationship. IdM and AD DNS Domains Systems joined to IdM can be distributed over multiple DNS domains. Deploy IdM clients in a DNS zone separate from those managed by Active Directory. The primary IdM DNS domain must have proper SRV records to support AD trusts. Note In some environments with trusts between IdM and AD, you can install an IdM client on a host that is part of the Active Directory DNS domain. The host can then benefit from the Linux-focused features of IdM. This is not a recommended configuration and has some limitations. See Configuring IdM clients in an Active Directory DNS domain for more details. You can acquire a list of the required SRV records specific to your system setup by running the following command: The generated list can look for example like this: For other DNS domains that are part of the same IdM realm, it is not required for the SRV records to be configured when the trust to AD is configured. The reason is that AD domain controllers do not use SRV records to discover KDCs but rather base the KDC discovery on name suffix routing information for the trust. 34.6.2. Configuring a DNS forward zone in the IdM Web UI You can add a DNS forward zone to the Identity Management (IdM) server by using the IdM Web UI. With DNS forward zones, you can forward DNS queries for a specific zone to a different DNS server. For example, you can forward DNS queries for the Active Directory (AD) domain to an AD DNS server. Prerequisites Access to the IdM Web UI with a user account that has administrator rights. Correctly configured DNS server. Procedure Log in to the IdM Web UI with administrator privileges. Click the Network Services tab. Click the DNS tab. In the drop down menu, click DNS Forward Zones . Click the Add button. In the Add DNS forward zone dialog box, add a zone name. In the Zone forwarders item, click the Add button. In the Zone forwarders field, add the IP address of the server for which you want to create the forward zone. Click the Add button. The forwarded zone has been added to the DNS settings and you can verify it in the DNS Forward Zones settings. The Web UI informs you about success with the following pop-up message: DNS Forward Zone successfully added. Note After adding a forward zone to the configuration, the Web UI might display a warning about a DNSSEC validation failure. DNSSEC (Domain Name System Security Extensions) secures DNS data with a digital signature to protect DNS from attacks. This service is enabled by default in the IdM server. The warning appears because the remote DNS server does not use DNSSEC. Enable DNSSEC on the remote DNS server. If you cannot enable DNSSEC validation on the remote server, you can disable DNSSEC in the IdM server: Choose the appropriate configuration file to edit: For IdM servers running RHEL 8.0 or RHEL 8.1, open the /etc/named.conf file. For IdM servers running RHEL 8.2 or later, open the /etc/named/ipa-options-ext.conf file. Add the following DNSSEC parameters: Save and close the configuration file. Restart the DNS service: Note that DNSSEC is only available as Technology Preview in IdM. Verification Use the nslookup command with the name of the remote DNS server: If you configured the domain forwarding correctly, the IP address of the remote DNS server is displayed. Additional resources Accessing the IdM Web UI in a web browser 34.6.3. Configuring a DNS forward zone in the CLI You can add a new DNS forward zone to the Identity Management (IdM) server using the command line (CLI). With DNS forward zones, you can forward DNS queries for a specific zone to a different DNS server. For example, you can forward DNS queries for the Active Directory (AD) domain to an AD DNS server. Prerequisites Access to the CLI with a user account that has administrator rights. Correctly configured DNS server. Procedure Create a DNS forward zone for the AD domain, and specify the IP address of the remote DNS server with the --forwarder option: Note You might see a warning about a DNSSEC validation failure in the /var/log/messages system logs after adding a new forward zone to the configuration: DNSSEC (Domain Name System Security Extensions) secures DNS data with a digital signature to protect DNS from attacks. This service is enabled by default in the IdM server. The warning appears because the remote DNS server does not use DNSSEC. Enable DNSSEC on the remote DNS server. If you cannot enable DNSSEC validation on the remote server, you can disable DNSSEC in the IdM server: Choose the appropriate configuration file to edit: For IdM servers running RHEL 8.0 or RHEL 8.1, open the /etc/named.conf file. For IdM servers running RHEL 8.2 or later, open the /etc/named/ipa-options-ext.conf file. Add the following DNSSEC parameters: Save and close the configuration file. Restart the DNS service: Note that DNSSEC is only available as Technology Preview in IdM. Verification Use the nslookup command with the name of the remote DNS server: If the domain forwarding is configured correctly, the nslookup request displays an IP address of the remote DNS server. 34.6.4. Configuring DNS forwarding in AD Follow this procedure to set up a DNS forwarding in Active Directory (AD) for the Identity Management (IdM) server. Prerequisites Windows Server with AD installed. DNS port open on both servers. Procedure Log in to the Windows Server. Open Server Manager . Open DNS Manager . In Conditional Forwarders , add a new conditional forwarder with: The IdM server IP address A fully qualified domain name, for example, server.idm.example.com Save the settings. 34.6.5. Verifying the DNS configuration Before configuring trust, verify that the Identity Management (IdM) and Active Directory (AD) servers can resolve themselves and each other. Prerequisites You are logged in with an account that has sudo permissions. Procedure Run a DNS query for the Kerberos over UDP and LDAP over TCP service records. The commands return the SRV records for the IdM servers. Run a DNS query for the TXT record with the IdM Kerberos realm name. The returned value should match the Kerberos realm you specified when installing IdM. If the steps did not return all the expected records, update the DNS configuration with the missing records: If your IdM environment uses an integrated DNS server, enter the ipa dns-update-system-records command without any options to update your system records: If your IdM environment does not use an integrated DNS server: On the IdM server, export the IdM DNS records into a file: The command creates a file named dns_records_file.nsupdate with the relevant IdM DNS records. Submit a DNS update request to your DNS server using the nsupdate utility and the dns_records_file.nsupdate file. For more information, see Updating External DNS Records Using nsupdate in RHEL 7 documentation. Alternatively, refer to your DNS server documentation for adding DNS records. Verify that IdM is able to resolve service records for AD with a command that runs a DNS query for Kerberos and LDAP over TCP service records: 34.7. Configuring IdM clients in an Active Directory DNS domain If you have client systems in a DNS domain controlled by Active Directory (AD) and you require those clients to join the IdM Server to benefit from its RHEL features, you can configure users to access a client using a host name from the AD DNS domain. Important This configuration is not recommended and has limitations. Always deploy IdM clients in a DNS zone separate from the ones owned by AD and access IdM clients using their IdM host names. Your IdM client configuration depends on whether you require single sign-on with Kerberos. 34.7.1. Configuring an IdM client without Kerberos single sign-on Password authentication is the only authentication method that is available for users to access resources on IdM clients if the IdM clients are in an Active Directory DNS domain. Follow this procedure to configure your client without Kerberos single sign-on. Procedure Install the IdM client with the --domain=IPA_DNS_Domain option to ensure the System Security Services Daemon (SSSD) can communicate with the IdM servers: This option disables the SRV record auto-detection for the Active Directory DNS domain. Open the /etc/krb5.conf configuration file and locate the existing mapping for the Active Directory domain in the [domain_realm] section. Replace both lines with an entry mapping the fully qualified domain name (FQDN) of the Linux clients in the Active Directory DNS zone to the IdM realm: By replacing the default mapping, you prevent Kerberos from sending its requests for the Active Directory domain to the IdM Kerberos Distribution Center (KDC). Instead Kerberos uses auto-discovery through SRV DNS records to locate the KDC. 34.7.2. Requesting SSL certificates without single sign-on After you configure an IdM client without Kerberos single sign-on, you can set up SSL-based services. SSL-based services require a certificate with dNSName extension records that cover all system host names, because both original (A/AAAA) and CNAME records must be in the certificate. Currently, IdM only issues certificates to host objects in the IdM database. In this setup, where single sign-on is not enabled, IdM already contains a host object for the FQDN in its database. You can use certmonger to request a certificate using the FQDN. Prerequisites An IdM client configured without Kerberos single-sign on. Procedure Use certmonger to request a certificate using the FQDN: The certmonger service uses the default host key stored in the /etc/krb5.keytab file to authenticate to the IdM Certificate Authority (CA). 34.7.3. Configuring an IdM client with Kerberos single sign-on If you require Kerberos single sign-on to access resources on the IdM client, the client must be within the IdM DNS domain, for example idm-client.idm.example.com . You must create a CNAME record idm-client.ad.example.com in the Active Directory DNS domain pointing to the A/AAAA record of the IdM client. For Kerberos-based application servers, MIT Kerberos supports a method to allow the acceptance of any host-based principal available in the application's keytab. Procedure On the IdM client, disable the strict checks on what Kerberos principal is used to target the Kerberos server by setting the following option in the [libdefaults] section of the /etc/krb5.conf configuration file: 34.7.4. Requesting SSL certificates with single sign-on After you disabled strict Kerberos principal checks on your IdM client, you can set up SSL-based services. SSL-based services require a certificate with dNSName extension records that cover all system host names, because both original (A/AAAA) and CNAME records must be in the certificate. Currently, IdM only issues certificates to host objects in the IdM database. Follow this procedure to create a host object for ipa-client.example.com in IdM and make sure the real IdM machine's host object is able to manage this host. Prerequisites You have disabled the strict checks on what Kerberos principal is used to target the Kerberos server. Procedure Create a new host object on the IdM server: Use the --force option, because the host name is a CNAME and not an A/AAAA record. On the IdM server, allow the IdM DNS host name to manage the Active Directory host entry in the IdM database: Your can now request an SSL certificate for your IdM client with the dNSName extension record for its host name within the Active Directory DNS domain: 34.8. Setting up a trust You can configure the Identity Management (IdM)/Active Directory (AD) trust on the IdM side using the command line. Prerequisites DNS is correctly configured. Both IdM and AD servers must be able to resolve each other names. For details, see Configuring DNS and realm settings for a trust . Supported versions of AD and IdM are deployed. For details, see Supported versions of Windows Server . You have obtained a Kerberos ticket. For details, see Using kinit to log in to IdM manually . 34.8.1. Preparing the IdM server for the trust Before you can establish a trust with AD, you must prepare the IdM domain using the ipa-adtrust-install utility on an IdM server. Note Any system where you run the ipa-adtrust-install command automatically becomes an AD trust controller. However, you must run ipa-adtrust-install only once on an IdM server. Prerequisites IdM server is installed. You have root privileges to install packages and restart IdM services. Procedure Install the required packages: Authenticate as the IdM administrative user: Run the ipa-adtrust-install utility: 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. The script prompts you that the /etc/samba/smb.conf already exists and will be rewritten: 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: When prompted, enter the NetBIOS name for the IdM domain or press Enter to accept the name suggested: You are prompted to run the SID generation task to create a SID for any existing users: This is a resource-intensive task, so if you have a high number of users, you can run this at another time. 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 . Make sure that DNS is properly configured, as described in Verifying the DNS configuration for a trust . Important Red Hat strongly recommends you verify the DNS configuration as described in Verifying the DNS configuration for a trust every time after running ipa-adtrust-install , especially if IdM or AD do not use integrated DNS servers. Restart the ipa service: Use the smbclient utility to verify that Samba responds to Kerberos authentication from the IdM side: 34.8.2. Setting up a trust agreement using the command line You can set up the trust agreement using the command line. The Identity Management (IdM) server allows you to configure three types of trust agreements: One-way trust - default option. One-way trust enables Active Directory (AD) users and groups to access resources in IdM, but not the other way around. The IdM domain trusts the AD forest, but the AD forest does not trust the IdM domain. Two-way trust - Two-way trust enables AD users and groups to access resources in IdM. You must configure a two-way trust for solutions such as Microsoft SQL Server that expect the S4U2Self and S4U2Proxy Microsoft extensions to the Kerberos protocol to work over a trust boundary. An application on a RHEL IdM host might request S4U2Self or S4U2Proxy information from an Active Directory domain controller about an AD user, and a two-way trust provides this feature. Note that this two-way trust functionality does not allow IdM users to login to Windows systems, and the two-way trust in IdM does not give the users any additional rights compared to the one-way trust solution in AD. To create the two-way trust, add the following option to the command: --two-way=true External trust - a trust relationship between IdM and an AD domain in different forests. While a forest trust always requires establishing a trust between IdM and the root domain of an Active Directory forest, an external trust can be established from IdM to a domain within a forest. This is only recommended if it is not possible to establish a forest trust between forest root domains due to administrative or organizational reasons. To create the external trust, add the following option to the command: --external=true The steps below show you how to create a one-way trust agreement. Prerequisites User name and password of a Windows administrator. You have prepared the IdM server for the trust . Procedure Create a trust agreement for the AD domain and the IdM domain by using the ipa trust-add command: To have SSSD automatically generate UIDs and GIDs for AD users based on their SID, create a trust agreement with the Active Directory domain ID range type. This is the most common configuration. If you have configured POSIX attributes for your users in Active Directory (such as uidNumber and gidNumber ) and you want SSSD to process this information, create a trust agreement with the Active Directory domain with POSIX attributes ID range type: Warning If you do not specify an ID Range type when creating a trust, IdM attempts to automatically select the appropriate range type by requesting details from AD domain controllers in the forest root domain. If IdM does not detect any POSIX attributes, the trust installation script selects the Active Directory domain ID range. If IdM detects any POSIX attributes in the forest root domain, the trust installation script selects the Active Directory domain with POSIX attributes ID range and assumes that UIDs and GIDs are correctly defined in AD. If POSIX attributes are not correctly set in AD, you will not be able to resolve AD users. For example, if the users and groups that need access to IdM systems are not part of the forest root domain, but instead are located in a child domain of the forest domain, the installation script might not detect the POSIX attributes defined in the child AD domain. In this case, explicitly choose the POSIX ID range type when establishing the trust. 34.8.3. Setting up a trust agreement in the IdM Web UI You can configure the Identity Management (IdM)/Active Directory (AD) trust agreement on the IdM side using the IdM Web UI. Prerequisites DNS is correctly configured. Both IdM and AD servers must be able to resolve each other names. Supported versions of AD and IdM are deployed. You have obtained a Kerberos ticket. Before creating a trust in the Web UI, prepare the IdM server for the trust as described in: Preparing the IdM server for the trust . You are logged in as an IdM administrator. For details, see Accessing the IdM Web UI in a web browser . Procedure In the IdM Web UI, click the IPA Server tab. In the IPA Server tab, click the Trusts tab. In the drop down menu, select the Trusts option. Click the Add button. In the Add Trust dialog box, enter the name of the Active Directory domain. In the Account and Password fields, add the administrator credentials of the Active Directory administrator. Optional: Select Two-way trust , if you want to enable AD users and groups to access resources in IdM. However, the two-way trust in IdM does not give the users any additional rights compared to the one-way trust solution in AD. Both solutions are considered equally secure because of default cross-forest trust SID filtering settings. Optional: Select External trust if you are configuring a trust with an AD domain that is not the root domain of an AD forest. While a forest trust always requires establishing a trust between IdM and the root domain of an Active Directory forest, you can establish an external trust from IdM to any domain within an AD forest. Optional: By default, the trust installation script tries to detect the appropriate ID range type. You can also explicitly set the ID range type by choosing one of the following options: To have SSSD automatically generate UIDs and GIDs for AD users based on their SID, select the Active Directory domain ID range type. This is the most common configuration. If you have configured POSIX attributes for your users in Active Directory (such as uidNumber and gidNumber ) and you want SSSD to process this information, select the Active Directory domain with POSIX attributes ID range type. Warning If you leave the Range type setting on the default Detect option, IdM attempts to automatically select the appropriate range type by requesting details from AD domain controllers in the forest root domain. If IdM does not detect any POSIX attributes, the trust installation script selects the Active Directory domain ID range. If IdM detects any POSIX attributes in the forest root domain, the trust installation script selects the Active Directory domain with POSIX attributes ID range and assumes that UIDs and GIDs are correctly defined in AD. If POSIX attributes are not correctly set in AD, you will not be able to resolve AD users. For example, if the users and groups that need access to IdM systems are not part of the forest root domain, but instead are located in a child domain of the forest domain, the installation script might not detect the POSIX attributes defined in the child AD domain. In this case, explicitly choose the POSIX ID range type when establishing the trust. Click Add . Verification If the trust has been successfully added to the IdM server, you can see the green pop-up window in the IdM Web UI. It means that the: Domain name exists User name and password of the Windows Server has been added correctly. Now you can continue to test the trust connection and Kerberos authentication. 34.8.4. Setting up a trust agreement using Ansible You can set up a one-way trust agreement between Identity Management (IdM) and Active Directory (AD) by using an Ansible playbook. You can configure three types of trust agreements: One-way trust - default option. One-way trust enables Active Directory (AD) users and groups to access resources in IdM, but not the other way around. The IdM domain trusts the AD forest, but the AD forest does not trust the IdM domain. Two-way trust - Two-way trust enables AD users and groups to access resources in IdM. You must configure a two-way trust for solutions such as Microsoft SQL Server that expect the S4U2Self and S4U2Proxy Microsoft extensions to the Kerberos protocol to work over a trust boundary. An application on a RHEL IdM host might request S4U2Self or S4U2Proxy information from an Active Directory domain controller about an AD user, and a two-way trust provides this feature. Note that this two-way trust functionality does not allow IdM users to login to Windows systems, and the two-way trust in IdM does not give the users any additional rights compared to the one-way trust solution in AD. To create the two-way trust, add the following variable to the playbook task below: two_way: true External trust - a trust relationship between IdM and an AD domain in different forests. While a forest trust always requires establishing a trust between IdM and the root domain of an Active Directory forest, an external trust can be established from IdM to a domain within a forest. This is only recommended if it is not possible to establish a forest trust between forest root domains due to administrative or organizational reasons. To create the external trust, add the following variable to the playbook task below: external: true Prerequisites User name and password of a Windows administrator. The IdM admin password. You have prepared the IdM server for the trust . You are using the 4.8.7 version of IdM or later. To view the version of IdM you have installed on your server, run ipa --version . You have configured your Ansible control node to meet the following requirements: You are using Ansible version 2.13 or later. You have installed the ansible-freeipa package. The example assumes that in the ~/ MyPlaybooks / directory, you have created an Ansible inventory file with the fully-qualified domain name (FQDN) of the IdM server. The example assumes that the secret.yml Ansible vault stores your ipaadmin_password . The target node, that is the node on which the ansible-freeipa module is executed, is part of the IdM domain as an IdM client, server or replica. Procedure Navigate to your ~/ MyPlaybooks / directory: Select one of the following scenarios based on your use case: To create an ID mapping trust agreement, in which SSSD automatically generates UIDs and GIDs for AD users and groups based on their SIDs, create an add-trust.yml playbook with the following content: In the example: realm defines the AD realm name string. admin defines the AD domain administrator string. password defines the AD domain administrator's password string. To create a POSIX trust agreement, in which SSSD processes POSIX attributes stored in AD, such as uidNumber and gidNumber , create an add-trust.yml playbook with the following content: To create a trust agreement in which IdM attempts to automatically select the appropriate range type, ipa-ad-trust or ipa-ad-trust-posix , by requesting details from AD domain controllers in the forest root domain, create an add-trust.yml playbook with the following content: Warning If you do not specify an ID range type when creating a trust, and if IdM does not detect any POSIX attributes in the AD forest root domain, the trust installation script selects the Active Directory domain ID range. If IdM detects any POSIX attributes in the forest root domain, the trust installation script selects the Active Directory domain with POSIX attributes ID range and assumes that UIDs and GIDs are correctly defined in AD. However, if POSIX attributes are not correctly set in AD, you will not be able to resolve AD users. For example, if the users and groups that need access to IdM systems are not part of the forest root domain, but instead are located in a child domain of the forest domain, the installation script might not detect the POSIX attributes defined in the child AD domain. In this case, explicitly choose the POSIX ID range type when establishing the trust. Save the file. Run the Ansible playbook. Specify the playbook file, the file storing the password protecting the secret.yml file, and the inventory file: Additional resources /usr/share/doc/ansible-freeipa/README-trust.md /usr/share/doc/ansible-freeipa/playbooks/trust 34.8.5. Verifying the Kerberos configuration To verify the Kerberos configuration, test if it is possible to obtain a ticket for an Identity Management (IdM) user and if the IdM user can request service tickets. Procedure Request a ticket for an Active Directory (AD) user: Request service tickets for a service within the IdM domain: If the AD service ticket is successfully granted, there is a cross-realm ticket-granting ticket (TGT) listed with all of the other requested tickets. The TGT is named krbtgt/IPA.DOMAIN@AD.DOMAIN. The localauth plug-in maps Kerberos principals to local System Security Services Daemon (SSSD) user names. This allows AD users to use Kerberos authentication and access Linux services, which support GSSAPI authentication directly. 34.8.6. Verifying the trust configuration on IdM Before configuring trust, verify that the Identity Management (IdM) and Active Directory (AD) servers can resolve themselves and each other. Prerequisites You need to be logged in with administrator privileges. Procedure Run a DNS query for the MS DC Kerberos over UDP and LDAP over TCP service records. These commands list all IdM servers on which ipa-adtrust-install has been executed. The output is empty if ipa-adtrust-install has not been executed on any IdM server, which is typically before establishing the first trust relationship. Run a DNS query for the Kerberos and LDAP over TCP service records to verify that IdM is able to resolve service records for AD: 34.8.7. Verifying the trust configuration on AD After configuring the trust, verify that: The Identity Management (IdM)-hosted services are resolvable from the Active Directory (AD) server. AD services are resolvable from the AD server. Prerequisites You need to be logged in with administrator privileges. Procedure On the AD server, set the nslookup.exe utility to look up service records. Enter the domain name for the Kerberos over UDP and LDAP over TCP service records. Change the service type to TXT and run a DNS query for the TXT record with the IdM Kerberos realm name. Run a DNS query for the MS DC Kerberos over UDP and LDAP over TCP service records. Active Directory only expects to discover domain controllers that can respond to AD-specific protocol requests, such as other AD domain controllers and IdM trust controllers. Use the ipa-adtrust-install tool to promote an IdM server to a trust controller, and you can verify which servers are trust controllers with the ipa server-role-find --role 'AD trust controller' command. Verify that AD services are resolvable from the AD server. Enter the domain name for the Kerberos over UDP and LDAP over TCP service records. 34.8.8. Creating a trust agent A trust agent is an IdM server that can perform identity lookups against AD domain controllers. For example, if you are creating a replica of an IdM server that has a trust with Active Directory, you can set up the replica as a trust agent. A replica does not automatically have the AD trust agent role installed. Prerequisites IdM is installed with an Active Directory trust. The sssd-tools package is installed. Procedure On an existing trust controller, run the ipa-adtrust-install --add-agents command: The command starts an interactive configuration session and prompts you for the information required to set up the agent. Restart the IdM service on the trust agent. Remove all entries from the SSSD cache on the trust agent: Verify that the replica has the AD trust agent role installed:. Additional resources ipa-adtrust-install(1) man page on your system Trust controllers and trust agents 34.8.9. Enabling automatic private group mapping for a POSIX ID range on the CLI By default, SSSD does not map private groups for Active Directory (AD) users if you have established a POSIX trust that relies on POSIX data stored in AD. If any AD users do not have primary groups configured, IdM is not be able to resolve them. This procedure explains how to enable automatic private group mapping for an ID range by setting the hybrid option for the auto_private_groups SSSD parameter on the command line. As a result, IdM is able to resolve AD users that do not have primary groups configured in AD. Prerequisites You have successfully established a POSIX cross-forest trust between your IdM and AD environments. Procedure Display all ID ranges and make note of the AD ID range you want to modify. Adjust the automatic private group behavior for the AD ID range with the ipa idrange-mod command. Reset the SSSD cache to enable the new setting. Additional resources Options for automatically mapping private groups for AD users 34.8.10. Enabling automatic private group mapping for a POSIX ID range in the IdM WebUI By default, SSSD does not map private groups for Active Directory (AD) users if you have established a POSIX trust that relies on POSIX data stored in AD. If any AD users do not have primary groups configured, IdM is not be able to resolve them. This procedure explains how to enable automatic private group mapping for an ID range by setting the hybrid option for the auto_private_groups SSSD parameter in the Identity Management (IdM) WebUI. As a result, IdM is able to resolve AD users that do not have primary groups configured in AD. Prerequisites You have successfully established a POSIX cross-forest trust between your IdM and AD environments. Procedure Log into the IdM Web UI with your user name and password. Open the IPA Server ID Ranges tab. Select the ID range you want to modify, such as AD.EXAMPLE.COM_id_range . From the Auto private groups drop down menu, select the hybrid option. Click the Save button to save your changes. Additional resources Options for automatically mapping private groups for AD users 34.9. Troubleshooting setting up a cross-forest trust Learn more about troubleshooting the process of configuring a cross-forest trust between your Identity Management (IdM) environment and an Active Directory (AD) forest. 34.9.1. Sequence of events when establishing a cross-forest trust with AD When you use the ipa trust-add command to establish a cross-forest trust with an Active Directory (AD) Domain Controller (DC), the command operates on behalf of the user who ran the command and performs the following actions on the IdM server. If you have trouble establishing a cross-forest trust, you can use this list to help narrow down and troubleshoot your issue. Part 1: The command verifies settings and inputs Verify that the IdM server has the Trust Controller role. Validate the options passed to the ipa trust-add command. Validate the ID range associated with a trusted forest root domain. If you did not specify the ID range type and properties as options to the ipa trust-add command, they are discovered from Active Directory. Part 2: The command attempts to establish a trust to an Active Directory domain Create a separate trust object for each trust direction. Each of the objects get created on both sides (IdM and AD). If you are establishing a one-way trust, only one object is created on each side. The IdM server uses the Samba suite to handle domain controller capabilities for Active Directory and creates a trust object on the target AD PDC: The IdM server establishes a secure connection to the IPCUSD share on the target DC. Since RHEL 8.4, the connection requires at least the SMB3 protocol with Windows Server 2012 and above to ensure the connection is sufficiently secure with AES-based encryption used for the session. The IdM server queries for the presence of the trusted domain object (TDO) using an LSA QueryTrustedDomainInfoByName call. If the TDO is already present, remove it with an LSA DeleteTrustedDomain call. Note This call fails if the AD user account used to establish the trust does not have full Enterprise Admin (EA) or Domain Admin (DA) privileges for the forest root, such as members of the Incoming Forest Trust Builders group. If the old TDO is not automatically removed, an AD Administrator must manually remove it from AD. The IdM server creates a new TDO with an LSA CreateTrustedDomainEx2 call. The TDO credentials are randomly generated using a Samba-provided password generator with 128 random characters. The new TDO is then modified with an LSA SetInformationTrustedDomain call to make sure encryption types supported by the trust are set properly: The RC4_HMAC_MD5 encryption type is enabled, even if there are no RC4 keys in use, due to how Active Directory is designed. AES128_CTS_HMAC_SHA1_96 and AES256_CTS_HMAC_SHA1_96 encryption types are enabled. For a forest trust, verify that in-forest domains can be reached transitively with an LSA SetInformationTrustedDomain call. Add trust topology information about the other forest (IdM in the case of communicating with AD, AD in the case of communicating with IdM) using an LSA RSetForestTrustInformation call. Note This step might cause a conflict for one of three reasons: A SID namespace conflict, reported as an LSA_SID_DISABLED_CONFLICT error. This conflict cannot be resolved. A NetBIOS namespace conflict, reported as an LSA_NB_DISABLED_CONFLICT error. This conflict cannot be resolved. A DNS namespace conflict with a top level name (TLN), reported as an LSA_TLN_DISABLED_CONFLICT error. The IdM server can automatically resolve a TLN conflict if it is caused by another forest. To resolve a TLN conflict, the IdM server performs the following steps: Retrieve forest trust information for the conflicting forest. Add an exclusion entry for the IdM DNS namespace to the AD forest. Set forest trust information for the forest we conflict on. Re-try establishing the trust to the original forest. The IdM server can only resolve these conflicts if you authenticated the ipa trust-add command with the privileges of an AD administrator that can change forest trusts. If you do not have access to those privileges, the administrator of the original forest must manually perform the steps above in the Active Directory Domains and Trusts section of the Windows UI. If it does not exist, create the ID range for the trusted domain. For a forest trust, query Active Directory domain controllers from the forest root for details about the forest topology. The IdM server uses this information to create additional ID ranges for any additional domains from the trusted forest. Additional resources Trust controllers and trust agents Overview Documents (Microsoft) Technical Documents (Microsoft) Privileged Accounts and Groups in Active Directory (Microsoft) 34.9.2. Checklist of prerequisites for establishing an AD trust You can use the following checklist to review the prerequisites for creating a trust with an AD domain. Table 34.4. Table Component Configuration Additional details Product versions Your Active Directory domain is using a supported version of Windows Server. Supported versions of Windows Server AD Administrator privileges The Active Directory administration account must be a member of one of the following groups: Enterprise Admin (EA) group in the AD forest Domain Admins (DA) group in the forest root domain for your AD forest Networking IPv6 support is enabled in the Linux kernel for all IdM servers. IPv6 requirements in IdM Date and time Verify the date and time settings on both servers match. Time service requirements for IdM Encryption types The following AD accounts have AES encryption keys: AD Administrator AD user accounts AD services If you have recently enabled AES encryption in AD, generate new AES keys with the following steps: Re-establish trust relationships between any AD domains in your forest. Change the passwords for the AD Administrator, user accounts, and services. Support for encryption types in IdM Enabling the AES encryption type in Active Directory using a GPO Firewall You have opened all necessary ports on IdM servers and AD Domain Controllers for bidirectional communication. Ports required for communication between IdM and AD DNS IdM and AD each have unique primary DNS domains. IdM and AD DNS domains do not overlap. Proper DNS service (SRV) records for LDAP and Kerberos services. You can resolve DNS records from all DNS domains in the trust. Kerberos realm names are the upper-case versions of primary DNS domain names. For example, DNS domain example.com has a corresponding Kerberos realm EXAMPLE.COM Configuring DNS and realm settings for a trust Topology Ensure you are attempting to establish a trust with an IdM server you have configured as a trust controller. Trust controllers and trust agents 34.9.3. Gathering debug logs of an attempt to establish an AD trust If you are experiencing issues with establishing a trust between an IdM environment and AD domain, use the following steps to enable detailed error logging so you can gather logs of an attempt to establish a trust. You can review these logs to help with your troubleshooting efforts, or you can provide them in a Red Hat Technical Support case. Prerequisites You need root permissions to restart IdM services. Procedure To enable debugging for the IdM server, create the file /etc/ipa/server.conf with the following contents. Restart the httpd service to load the debugging configuration. Stop the smb and winbind services. Set the debugging log level for the smb and winbind services. To enable debug logging for Samba client code used by the IdM framework, edit the /usr/share/ipa/smb.conf.empty configuration file to have the following contents. Remove Samba logs. Start the smb and winbind services. Print a timestamp as you attempt to establish a trust with verbose mode enabled. Review the following error log files for information about the failed request: /var/log/httpd/error_log /var/log/samba/log.* Disable debugging. Optional: If you are unable to determine the cause of the authentication issue: Collect and archive the log files you recently generated. Open a Red Hat Technical Support case and provide the timestamp and debug logs from the attempt. Additional resources IPA - AD Trust Troubleshooting 34.10. Troubleshooting client access to services in the other forest After configuring a trust between your Identity Management (IdM) and Active Directory (AD) environments, you might experience issues where a client in one domain is not able to access a service in the other domain. Use the following diagrams to troubleshoot the issue. 34.10.1. Flow of information when a host in the AD forest root domain requests services from an IdM server The following diagram explains the flow of information when an Active Directory (AD) client requests a service in the Identity Management (IdM) domain. If you have trouble accessing IdM services from AD clients, you can use this information to narrow your troubleshooting efforts and identify the source of the issue. The AD client contacts the AD Kerberos Distribution Center (KDC) to perform a TGS Request for the service in the IdM domain. The AD KDC recognizes that the service belongs to the trusted IdM domain. The AD KDC sends the client a cross-realm ticket-granting ticket (TGT), along with a referral to the trusted IdM KDC. The AD client uses the cross-realm TGT to request a ticket to the IdM KDC. The IdM KDC validates the Privileged Attribute Certificate (MS-PAC) that is transmitted with the cross-realm TGT. The IPA-KDB plugin might check the LDAP directory to see if foreign principals are allowed to get tickets for the requested service. The IPA-KDB plugin decodes the MS-PAC, verifies, and filters the data. It performs lookups in the LDAP server to check if it needs to augment the MS-PAC with additional information, such as local groups. The IPA-KDB plugin then encodes the PAC, signs it, attaches it to the service ticket, and sends it to the AD client. The AD client can now contact the IdM service using the service ticket issued by IdM KDC. 34.10.2. Flow of information when a host in an AD child domain requests services from an IdM server The following diagram explains the flow of information when an Active Directory (AD) host in a child domain requests a service in the Identity Management (IdM) domain. In this scenario, the AD client contacts the Kerberos Distribution Center (KDC) in the child domain, then contacts the KDC in the AD forest root, and finally contacts the IdM KDC to request access to the IdM service. If you have trouble accessing IdM services from AD clients, and your AD client belongs to a domain that is a child domain of an AD forest root, you can use this information to narrow your troubleshooting efforts and identify the source of the issue. The AD client contacts the AD Kerberos Distribution Center (KDC) in its own domain to perform a TGS Request for the service in the IdM domain. The AD KDC in child.ad.example.com , the child domain, recognizes that the service belongs to the trusted IdM domain. The AD KDC in the child domain sends the client a referral ticket for the AD forest root domain ad.example.com . The AD client contacts the KDC in the AD forest root domain for the service in the IdM domain. The KDC in the forest root domain recognizes that the service belongs to the trusted IdM domain. The AD KDC sends the client a cross-realm ticket-granting ticket (TGT), along with a referral to the trusted IdM KDC. The AD client uses the cross-realm TGT to request a ticket to the IdM KDC. The IdM KDC validates the Privileged Attribute Certificate (MS-PAC) that is transmitted with the cross-realm TGT. The IPA-KDB plugin might check the LDAP directory to see if foreign principals are allowed to get tickets for the requested service. The IPA-KDB plugin decodes the MS-PAC, verifies, and filters the data. It performs lookups in the LDAP server to check if it needs to augment the MS-PAC with additional information, such as local groups. The IPA-KDB plugin then encodes the PAC, signs it, attaches it to the service ticket, and sends it to the AD client. The AD client can now contact the IdM service using the service ticket issued by IdM KDC. 34.10.3. Flow of information when an IdM client requests services from an AD server The following diagram explains the flow of information when an Identity Management (IdM) client requests a service in the Active Directory (AD) domain when you have configured a two-way trust between IdM and AD. If you have trouble accessing AD services from IdM clients, you can use this information to narrow your troubleshooting efforts and identify the source of the issue. Note By default, IdM establishes a one-way trust to AD, which means it is not possible to issue cross-realm ticket-granting ticket (TGT) for resources in an AD forest. To be able to request tickets to services from trusted AD domains, configure a two-way trust. The IdM client requests a ticket-granting ticket (TGT) from the IdM Kerberos Distribution Center (KDC) for the AD service it wants to contact. The IdM KDC recognizes that the service belongs to the AD realm, verifies that the realm is known and trusted, and that the client is allowed to request services from that realm. Using information from the IdM Directory Server about the user principal, the IdM KDC creates a cross-realm TGT with a Privileged Attribute Certificate (MS-PAC) record about the user principal. The IdM KDC sends back a cross-realm TGT to the IdM client. The IdM client contacts the AD KDC to request a ticket for the AD service, presenting the cross-realm TGT that contains the MS-PAC provided by the IdM KDC. The AD server validates and filters the PAC, and returns a ticket for the AD service. The IPA client can now contact the AD service. Additional resources One-way trusts and two-way trusts 34.11. Removing the trust using the command line You can remove the Identity Management (IdM)/Active Directory (AD) trust on the IdM side using the command line. Prerequisites You have obtained a Kerberos ticket as an IdM administrator. For details, see Logging in to IdM in the Web UI: Using a Kerberos ticket . Procedure Use the ipa trust-del command to remove the trust configuration from IdM. Remove the trust object from your Active Directory configuration. Note Removing the trust configuration does not automatically remove the ID range IdM has created for AD users. This way, if you add the trust again, the existing ID range is re-used. Also, if AD users have created files on an IdM client, their POSIX IDs are preserved in the file metadata. To remove all information related to an AD trust, remove the AD user ID range after removing the trust configuration and trust object: Verification Use the ipa trust-show command to confirm that the trust has been removed. 34.12. Removing the trust using the IdM Web UI You can remove the Identity Management (IdM)/Active Directory (AD) trust using the IdM Web UI. Prerequisites You have obtained a Kerberos ticket. For details, see Logging in to IdM in the Web UI: Using a Kerberos ticket . Procedure Log in to the IdM Web UI with administrator privileges. For details, see Accessing the IdM Web UI in a web browser . In the IdM Web UI, click the IPA Server tab. In the IPA Server tab, click the Trusts tab. Select the trust you want to remove. Click the Delete button. In the Remove trusts dialog box, click Delete . Remove the trust object from your Active Directory configuration. Note Removing the trust configuration does not automatically remove the ID range IdM has created for AD users. This way, if you add the trust again, the existing ID range is re-used. Also, if AD users have created files on an IdM client, their POSIX IDs are preserved in the file metadata. To remove all information related to an AD trust, remove the AD user ID range in the ID Ranges tab after removing the trust configuration and trust object. Verification If the trust has been successfully deleted, the Web UI displays a green pop-up with the text: 34.13. Removing the trust using Ansible You can remove the Identity Management (IdM)/Active Directory (AD) trust on the IdM side by using an Ansible playbook. Prerequisites You have obtained a Kerberos ticket as an IdM administrator. For details, see Logging in to IdM in the Web UI: Using a Kerberos ticket . You have configured your Ansible control node to meet the following requirements: You are using Ansible version 2.13 or later. You have installed the ansible-freeipa package. The example assumes that in the ~/ MyPlaybooks / directory, you have created an Ansible inventory file with the fully-qualified domain name (FQDN) of the IdM server. The example assumes that the secret.yml Ansible vault stores your ipaadmin_password . The target node, that is the node on which the ansible-freeipa module is executed, is part of the IdM domain as an IdM client, server or replica. Procedure Navigate to your ~/ MyPlaybooks / directory: Create an del-trust.yml playbook with the following content: In the example, realm defines the AD realm name string. Save the file. Run the Ansible playbook. Specify the playbook file, the file storing the password protecting the secret.yml file, and the inventory file: Note Removing the trust configuration does not automatically remove the ID range IdM has created for AD users. This way, if you add the trust again, the existing ID range is re-used. Also, if AD users have created files on an IdM client, their POSIX IDs are preserved in the file metadata. To remove all information related to an AD trust, remove the AD user ID range after removing the trust configuration and trust object: Verification Use the ipa trust-show command to confirm that the trust has been removed. Additional resources /usr/share/doc/ansible-freeipa/README-trust.md /usr/share/doc/ansible-freeipa/playbooks/trust 34.14. Removing an ID range after removing a trust to AD If you have removed a trust between your IdM and Active Directory (AD) environments, you might want to remove the ID range associated with it. Warning IDs allocated to ID ranges associated with trusted domains might still be used for ownership of files and directories on systems enrolled into IdM. If you remove the ID range that corresponds to an AD trust that you have removed, you will not be able to resolve the ownership of any files and directories owned by AD users. Prerequisites You have removed a trust to an AD environment. Procedure Display all the ID ranges that are currently in use: Identify the name of the ID range associated with the trust you have removed. The first part of the name of the ID range is the name of the trust, for example AD.EXAMPLE.COM_id_range . Remove the range: Restart the SSSD service to remove references to the ID range you have removed.

Commands:
C:\> gpupdate /force /target:computer
update-crypto-policies --set DEFAULT:AD-SUPPORT Setting system policy to DEFAULT:AD-SUPPORT Note: System-wide crypto policies are applied on application start-up. It is recommended to restart the system for the change of policies to fully take place.
[libdefaults] permitted_enctypes = aes256-cts-hmac-sha1-96 aes256-cts-hmac-sha384-192 camellia256-cts-cmac aes128-cts-hmac-sha1-96 aes128-cts-hmac-sha256-128 camellia128-cts-cmac +rc4
ipa dns-update-system-records --dry-run
IPA DNS records: _kerberos-master._tcp.idm.example.com. 86400 IN SRV 0 100 88 server.idm.example.com. _kerberos-master._udp.idm.example.com. 86400 IN SRV 0 100 88 server.idm.example.com. _kerberos._tcp.idm.example.com. 86400 IN SRV 0 100 88 server.idm.example.com. _kerberos._tcp.idm.example.com. 86400 IN SRV 0 100 88 server.idm.example.com. _kerberos.idm.example.com. 86400 IN TXT "IDM.EXAMPLE.COM" _kpasswd._tcp.idm.example.com. 86400 IN SRV 0 100 464 server.idm.example.com. _kpasswd._udp.idm.example.com. 86400 IN SRV 0 100 464 server.idm.example.com. _ldap._tcp.idm.example.com. 86400 IN SRV 0 100 389 server.idm.example.com. _ipa-ca.idm.example.com. 86400 IN A 192.168.122.2
dnssec-enable no; dnssec-validation no;
systemctl restart named-pkcs11
nslookup ad.example.com Server: 192.168.122.2 Address: 192.168.122.2#53 No-authoritative answer: Name: ad.example.com Address: 192.168.122.3
ipa dnsforwardzone-add ad.example.com --forwarder= 192.168.122.3 --forward-policy=first
named-pkcs11[2572]: no valid DS resolving 'host.ad.example.com/A/IN': 192.168.100.25#53
dnssec-enable no; dnssec-validation no;
systemctl restart named-pkcs11
nslookup ad.example.com Server: 192.168.122.2 Address: 192.168.122.2#53 No-authoritative answer: Name: ad.example.com Address: 192.168.122.3
dig +short -t SRV _kerberos._udp.idm.example.com. 0 100 88 server.idm.example.com. dig +short -t SRV _ldap._tcp.idm.example.com. 0 100 389 server.idm.example.com.
dig +short -t TXT _kerberos.idm.example.com. "IDM.EXAMPLE.COM"
[admin@server ~]USD ipa dns-update-system-records
[admin@server ~]USD ipa dns-update-system-records --dry-run --out dns_records_file.nsupdate
dig +short -t SRV _kerberos._tcp.dc._msdcs.ad.example.com. 0 100 88 addc1.ad.example.com. dig +short -t SRV _ldap._tcp.dc._msdcs.ad.example.com. 0 100 389 addc1.ad.example.com.
ipa-client-install --domain=idm.example.com
.ad.example.com = IDM.EXAMPLE.COM ad.example.com = IDM.EXAMPLE.COM
idm-client.ad.example.com = IDM.EXAMPLE.COM
ipa-getcert request -r -f /etc/httpd/alias/server.crt -k /etc/httpd/alias/server.key -N CN=ipa-client.ad.example.com -D ipa-client.ad.example.com -K host/idm-client.ad.example.com@IDM.EXAMPLE.COM -U id-kp-serverAuth
ignore_acceptor_hostname = true
ipa host-add idm-client.ad.example.com --force
ipa host-add-managedby idm-client.ad.example.com --hosts=idm-client.idm.example.com
ipa-getcert request -r -f /etc/httpd/alias/server.crt -k /etc/httpd/alias/server.key -N CN=`hostname --fqdn` -D `hostname --fqdn` -D idm-client.ad.example.com -K host/idm-client.idm.example.com@IDM.EXAMPLE.COM -U id-kp-serverAuth
yum install ipa-server-trust-ad samba-client
kinit admin
ipa-adtrust-install
WARNING: The smb.conf already exists. Running ipa-adtrust-install will break your existing Samba configuration. Do you wish to continue? [no]: yes
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
Trust is configured but no NetBIOS domain name found, setting it now. Enter the NetBIOS name for the IPA domain. Only up to 15 uppercase ASCII letters, digits and dashes are allowed. Example: EXAMPLE. NetBIOS domain name [IDM]:
Do you want to run the ipa-sidgen task? [no]: yes
net conf setparm global 'rpc server dynamic port range' 55000-65000 firewall-cmd --add-port=55000-65000/tcp firewall-cmd --runtime-to-permanent
ipactl restart
smbclient -L ipaserver.idm.example.com -U user_name --use-kerberos=required lp_load_ex: changing to config backend registry Sharename Type Comment --------- ---- ------- IPCUSD IPC IPC Service (Samba 4.15.2)
ipa trust-add --type=ad ad.example.com --admin <ad_admin_username> --password --range-type=ipa-ad-trust
ipa trust-add --type=ad ad.example.com --admin <ad_admin_username> --password --range-type=ipa-ad-trust-posix
cd ~/ MyPlaybooks /
--- - name: Playbook to create a trust hosts: ipaserver vars_files: - /home/user_name/MyPlaybooks/secret.yml tasks: - name: ensure the trust is present ipatrust: ipaadmin_password: "{{ ipaadmin_password }}" realm: ad.example.com admin: Administrator password: secret_password state: present
--- - name: Playbook to create a trust hosts: ipaserver vars_files: - /home/user_name/MyPlaybooks/secret.yml tasks: - name: ensure the trust is present ipatrust: ipaadmin_password: "{{ ipaadmin_password }}" realm: ad.example.com admin: Administrator password: secret_password range_type: ipa-ad-trust-posix state: present
--- - name: Playbook to create a trust hosts: ipaserver vars_files: - /home/user_name/MyPlaybooks/secret.yml tasks: - name: ensure the trust is present ipatrust: ipaadmin_password: "{{ ipaadmin_password }}" realm: ad.example.com admin: Administrator password: secret_password state: present
ansible-playbook --vault-password-file=password_file -v -i inventory add-trust.yml
kinit user@AD.EXAMPLE.COM
kvno -S host server.idm.example.com
klist Ticket cache: KEYRING:persistent:0:krb_ccache_hRtox00 Default principal: user@AD.EXAMPLE.COM Valid starting Expires Service principal 03.05.2016 18:31:06 04.05.2016 04:31:01 host/server.idm.example.com@IDM.EXAMPLE.COM renew until 04.05.2016 18:31:00 03.05.2016 18:31:06 04.05.2016 04:31:01 krbtgt/IDM.EXAMPLE.COM@AD.EXAMPLE.COM renew until 04.05.2016 18:31:00 03.05.2016 18:31:01 04.05.2016 04:31:01 krbtgt/AD.EXAMPLE.COM@AD.EXAMPLE.COM renew until 04.05.2016 18:31:00
dig +short -t SRV _kerberos._udp.dc._msdcs.idm.example.com. 0 100 88 server.idm.example.com. dig +short -t SRV _ldap._tcp.dc._msdcs.idm.example.com. 0 100 389 server.idm.example.com.
dig +short -t SRV _kerberos._tcp.dc._msdcs.ad.example.com. 0 100 88 addc1.ad.example.com. dig +short -t SRV _ldap._tcp.dc._msdcs.ad.example.com. 0 100 389 addc1.ad.example.com.
C:\>nslookup.exe > set type=SRV
> _kerberos._udp.idm.example.com. _kerberos._udp.idm.example.com. SRV service location: priority = 0 weight = 100 port = 88 svr hostname = server.idm.example.com > _ldap._tcp.idm.example.com _ldap._tcp.idm.example.com SRV service location: priority = 0 weight = 100 port = 389 svr hostname = server.idm.example.com
C:\>nslookup.exe > set type=TXT > _kerberos.idm.example.com. _kerberos.idm.example.com. text = "IDM.EXAMPLE.COM"
C:\>nslookup.exe > set type=SRV > _kerberos._udp.dc._msdcs.idm.example.com. _kerberos._udp.dc._msdcs.idm.example.com. SRV service location: priority = 0 weight = 100 port = 88 svr hostname = server.idm.example.com > _ldap._tcp.dc._msdcs.idm.example.com. _ldap._tcp.dc._msdcs.idm.example.com. SRV service location: priority = 0 weight = 100 port = 389 svr hostname = server.idm.example.com
C:\>nslookup.exe > set type=SRV
> _kerberos._udp.dc._msdcs.ad.example.com. _kerberos._udp.dc._msdcs.ad.example.com. SRV service location: priority = 0 weight = 100 port = 88 svr hostname = addc1.ad.example.com > _ldap._tcp.dc._msdcs.ad.example.com. _ldap._tcp.dc._msdcs.ad.example.com. SRV service location: priority = 0 weight = 100 port = 389 svr hostname = addc1.ad.example.com
ipa-adtrust-install --add-agents
ipactl restart
sssctl cache-remove
ipa server-show new_replica.idm.example.com Enabled server roles: CA server, NTP server, AD trust agent
ipa idrange-find ---------------- 2 ranges matched ---------------- Range name: IDM.EXAMPLE.COM_id_range First Posix ID of the range: 882200000 Number of IDs in the range: 200000 Range type: local domain range Range name: AD.EXAMPLE.COM_id_range First Posix ID of the range: 1337000000 Number of IDs in the range: 200000 Domain SID of the trusted domain: S-1-5-21-4123312420-990666102-3578675309 Range type: Active Directory trust range with POSIX attributes ---------------------------- Number of entries returned 2 ----------------------------
ipa idrange-mod --auto-private-groups=hybrid AD.EXAMPLE.COM_id_range
sss_cache -E
[global] debug=True
systemctl restart httpd
systemctl stop smb winbind
net conf setparm global 'log level' 100
[global] log level = 100
rm /var/log/samba/log.*
systemctl start smb winbind
date; ipa -vvv trust-add --type=ad ad.example.com
mv /etc/ipa/server.conf /etc/ipa/server.conf.backup systemctl restart httpd systemctl stop smb winbind net conf setparm global 'log level' 0 mv /usr/share/ipa/smb.conf.empty /usr/share/ipa/smb.conf.empty.backup systemctl start smb winbind
tar -cvf debugging-trust.tar /var/log/httpd/error_log /var/log/samba/log.*
ipa trust-del ad_domain_name ------------------------------ Deleted trust " ad_domain_name " ------------------------------
ipa idrange-del AD.EXAMPLE.COM_id_range systemctl restart sssd
ipa trust-show ad.example.com ipa: ERROR: ad.example.com: trust not found
cd ~/ MyPlaybooks /
--- - name: Playbook to delete trust hosts: ipaserver vars_files: - /home/user_name/MyPlaybooks/secret.yml tasks: - name: ensure the trust is absent ipatrust: ipaadmin_password: "{{ ipaadmin_password }}" realm: ad.example.com state: absent
ansible-playbook --vault-password-file=password_file -v -i inventory del-trust.yml
ipa idrange-del AD.EXAMPLE.COM_id_range systemctl restart sssd
ipa trust-show ad.example.com ipa: ERROR: ad.example.com: trust not found
ipa idrange-find
ipa idrange-del AD.EXAMPLE.COM_id_range
systemctl restart sssd