idmap_nss - Man Page

Samba's idmap_nss Backend for Winbind

Description

The idmap_nss plugin provides a means to map Unix users and groups to Windows accounts​. This provides a simple means of ensuring that the SID for a Unix user named jsmith is reported as the one assigned to DOMAIN\jsmith which is necessary for reporting ACLs on files and printers stored on a Samba member server​.

Idmap Options

range = low - high

Defines the available matching UID and GID range for which the backend is authoritative​. Note that the range acts as a filter​. Returned UIDs or GIDs by NSS modules that fall outside the range are ignored and the corresponding maps discarded​. It is intended as a way to avoid accidental UID/GID overlaps between local and remotely defined IDs​.

use_upn = <yes | no>

Some NSS modules can return and handle UPNs and/or down-level logon names (e​.g​., DOMAIN\user or user@REALM)​.

If this parameter is enabled the returned names from NSS will be parsed and the resulting namespace will be used as the authoritative namespace instead of the IDMAP domain name​. Also, down-level logon names will be sent to NSS instead of the plain username to give NSS modules a hint about the user's correct domain​.

Default: no

Examples

This example shows how to use idmap_nss to obtain the local account ID's for its own domain (SAMBA) from NSS, whilst allocating new mappings for the default domain (*) and any trusted domains​.

	[global]
	idmap config * : backend = tdb
	idmap config * : range = 1000000-1999999

	idmap config SAMBA : backend  = nss
	idmap config SAMBA : range = 1000-999999

Author

The original Samba software and related utilities were created by Andrew Tridgell​. Samba is now developed by the Samba Team as an Open Source project similar to the way the Linux kernel is developed​.

Info

10/01/2026 Samba 4.25.0 System Administration tools