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integration

ID Ranges

Manage UID and GID ranges for POSIX attribute assignment and trust domain integration. ID ranges define allocatable ranges for user and group identifiers, ensuring no conflicts between local users and trusted domain users. Features include range creation with base IDs and sizes, domain and range type specification (local, AD trust with SID), automatic range detection for trusted domains, and range modification for scaling deployments.

5 commands
integration
uid gid ranges posix

Manage ID ranges used to map Posix IDs to SIDs and back.

There are two type of ID ranges which are both handled by this utility:

  • the ID ranges of the local domain
  • the ID ranges of trusted remote domains

Both types have the following attributes in common:

  • base-id: the first ID of the Posix ID range
  • range-size: the size of the range

With those two attributes a range object can reserve the Posix IDs starting with base-id up to but not including base-id+range-size exclusively.

Additionally an ID range of the local domain must set

  • rid-base: the first RID(*) of the corresponding RID range
  • secondary-rid-base: first RID of the secondary RID range

If the server is updated from a previous version and defines local ID ranges missing the rid-base and secondary-rid-base, it is recommended to use [ipa-idrange-fix]{.title-ref} command to identify the missing values and fix the ID ranges.

and an ID range of a trusted domain must set

  • rid-base: the first RID of the corresponding RID range
  • sid: domain SID of the trusted domain

and an ID range of a trusted domain may set

  • auto-private-groups: [true|false|hybrid] automatic creation of private groups

EXAMPLE: Add a new ID range for a trusted domain

Since there might be more than one trusted domain the domain SID must be given while creating the ID range.

ipa idrange-add —base-id=1200000 —range-size=200000 —rid-base=0 .. code-block:: console

—dom-sid=S-1-5-21-123-456-789 trusted_dom_range

This ID range is then used by the IPA server and the SSSD IPA provider to assign Posix UIDs to users from the trusted domain.

If e.g. a range for a trusted domain is configured with the following values:

base-id = 1200000

range-size = 200000

rid-base = 0

the RIDs 0 to 199999 are mapped to the Posix ID from 1200000 to 13999999. So RID 1000 <-> Posix ID 1201000

EXAMPLE: Add a new ID range for the local domain

To create an ID range for the local domain it is not necessary to specify a domain SID. But since it is possible that a user and a group can have the same value as Posix ID a second RID interval is needed to handle conflicts.

ipa idrange-add —base-id=1200000 —range-size=200000 —rid-base=1000 .. code-block:: console

—secondary-rid-base=1000000 local_range

The data from the ID ranges of the local domain are used by the IPA server internally to assign SIDs to IPA users and groups. The SID will then be stored in the user or group objects.

If e.g. the ID range for the local domain is configured with the values from the example above then a new user with the UID 1200007 will get the RID 1007. If this RID is already used by a group the RID will be 1000007. This can only happen if a user or a group object was created with a fixed ID because the automatic assignment will not assign the same ID twice. Since there are only users and groups sharing the same ID namespace it is sufficient to have only one fallback range to handle conflicts.

To find the Posix ID for a given RID from the local domain it has to be checked first if the RID falls in the primary or secondary RID range and the rid-base or the secondary-rid-base has to be subtracted, respectively, and the base-id has to be added to get the Posix ID.

Typically the creation of ID ranges happens behind the scenes and this CLI must not be used at all. The ID range for the local domain will be created during installation or upgrade from an older version. The ID range for a trusted domain will be created together with the trust by ‘ipa trust-add …’.

USE CASES

Add an ID range from a transitively trusted domain

If the trusted domain (A) trusts another domain (B) as well and this trust
is transitive 'ipa trust-add domain-A' will only create a range for
domain A.  The ID range for domain B must be added manually.

Add an additional ID range for the local domain

If the ID range of the local domain is exhausted, i.e. no new IDs can be
assigned to Posix users or groups by the DNA plugin, a new range has to be
created to allow new users and groups to be added. (Currently there is no
connection between this range CLI and the DNA plugin, but a future version
might be able to modify the configuration of the DNS plugin as well)

In general it is not necessary to modify or delete ID ranges. If there is no other way to achieve a certain configuration than to modify or delete an ID range it should be done with great care. Because UIDs are stored in the file system and are used for access control it might be possible that users are allowed to access files of other users if an ID range got deleted and reused for a different domain.

(*) The RID is typically the last integer of a user or group SID which follows the domain SID. E.g. if the domain SID is S-1-5-21-123-456-789 and a user from this domain has the SID S-1-5-21-123-456-789-1010 then 1010 is the RID of the user. RIDs are unique in a domain, 32bit values and are used for users and groups.

WARNING

DNA plugin in 389-ds will allocate IDs based on the ranges configured for the local domain. Currently the DNA plugin cannot be reconfigured itself based on the local ranges set via this family of commands.

Manual configuration change has to be done in the DNA plugin configuration for the new local range. Specifically, The dnaNextRange attribute of ‘cn=Posix IDs,cn=Distributed Numeric Assignment Plugin,cn=plugins,cn=config’ has to be modified to match the new range.

Commands

Command Description

idrange-add Add new ID range.

idrange-del Delete an ID range.

idrange-find Search for ranges.

idrange-mod Modify ID range.

idrange-show Display information about a range.

idrange-add

Usage: ipa [global-options] idrange-add NAME [options]

Add new ID range.

To add a new ID range you always have to specify

    --base-id
    --range-size

Additionally

    --rid-base
    --secondary-rid-base

may be given for a new ID range for the local domain while

    --auto-private-groups

may be given for a new ID range for a trusted AD domain and

    --rid-base
    --dom-sid

must be given to add a new range for a trusted AD domain.

WARNING

DNA plugin in 389-ds will allocate IDs based on the ranges configured for the local domain. Currently the DNA plugin cannot be reconfigured itself based on the local ranges set via this family of commands.

Manual configuration change has to be done in the DNA plugin configuration for the new local range. Specifically, The dnaNextRange attribute of ‘cn=Posix IDs,cn=Distributed Numeric Assignment Plugin,cn=plugins,cn=config’ has to be modified to match the new range.

Arguments

Argument Required Description

NAME yes Range name

Options

Option Description

--base-id BASE-ID First Posix ID of the range

--range-size RANGE-SIZE Number of IDs in the range

--rid-base RID-BASE First RID of the corresponding RID range

--secondary-rid-base SECONDARY-RID-BASE First RID of the secondary RID range

--dom-sid DOM-SID Domain SID of the trusted domain

--dom-name DOM-NAME Name of the trusted domain

--type TYPE ID range type, one of allowed values

--auto-private-groups AUTO-PRIVATE-GROUPS Auto creation of private groups, one of allowed values

--setattr SETATTR Set an attribute to a name/value pair. Format is attr=value.

--addattr ADDATTR Add an attribute/value pair. Format is attr=value. The attribute

--all Retrieve and print all attributes from the server. Affects command output.

--raw Print entries as stored on the server. Only affects output format.

idrange-del

Usage: ipa [global-options] idrange-del NAME [options]

Delete an ID range.

Arguments

Argument Required Description

NAME yes Range name

Options

Option Description

--continue Continuous mode: Don’t stop on errors.

idrange-find

Usage: ipa [global-options] idrange-find [CRITERIA] [options]

Search for ranges.

Arguments

Argument Required Description

CRITERIA no A string searched in all relevant object attributes

Options

Option Description

--name NAME Range name

--base-id BASE-ID First Posix ID of the range

--range-size RANGE-SIZE Number of IDs in the range

--rid-base RID-BASE First RID of the corresponding RID range

--secondary-rid-base SECONDARY-RID-BASE First RID of the secondary RID range

--dom-sid DOM-SID Domain SID of the trusted domain

--type TYPE ID range type, one of allowed values

--auto-private-groups AUTO-PRIVATE-GROUPS Auto creation of private groups, one of allowed values

--timelimit TIMELIMIT Time limit of search in seconds (0 is unlimited)

--sizelimit SIZELIMIT Maximum number of entries returned (0 is unlimited)

--all Retrieve and print all attributes from the server. Affects command output.

--raw Print entries as stored on the server. Only affects output format.

--pkey-only Results should contain primary key attribute only (“name”)

idrange-mod

Usage: ipa [global-options] idrange-mod NAME [options]

Modify ID range.

WARNING

DNA plugin in 389-ds will allocate IDs based on the ranges configured for the local domain. Currently the DNA plugin cannot be reconfigured itself based on the local ranges set via this family of commands.

Manual configuration change has to be done in the DNA plugin configuration for the new local range. Specifically, The dnaNextRange attribute of ‘cn=Posix IDs,cn=Distributed Numeric Assignment Plugin,cn=plugins,cn=config’ has to be modified to match the new range.

Arguments

Argument Required Description

NAME yes Range name

Options

Option Description

--base-id BASE-ID First Posix ID of the range

--range-size RANGE-SIZE Number of IDs in the range

--rid-base RID-BASE First RID of the corresponding RID range

--secondary-rid-base SECONDARY-RID-BASE First RID of the secondary RID range

--auto-private-groups AUTO-PRIVATE-GROUPS Auto creation of private groups, one of allowed values

--setattr SETATTR Set an attribute to a name/value pair. Format is attr=value.

--addattr ADDATTR Add an attribute/value pair. Format is attr=value. The attribute

--delattr DELATTR Delete an attribute/value pair. The option will be evaluated

--rights Display the access rights of this entry (requires —all). See ipa man page for details.

--all Retrieve and print all attributes from the server. Affects command output.

--raw Print entries as stored on the server. Only affects output format.

idrange-show

Usage: ipa [global-options] idrange-show NAME [options]

Display information about a range.

Arguments

Argument Required Description

NAME yes Range name

Options

Option Description

--rights Display the access rights of this entry (requires —all). See ipa man page for details.

--all Retrieve and print all attributes from the server. Affects command output.

--raw Print entries as stored on the server. Only affects output format.

Related Topics

trust user group