Which line should be added to smb.conf to avoid UID and GID inconsistencies across servers over SMB?

`ldap dn` is not a standard `smb.conf` parameter for specifying the LDAP server itself; it's typically used to specify the bind distinguished name for authentication.

`ldap server` is used to specify the LDAP server, but it doesn't configure the `idmap` backend to use LDAP for UID/GID mapping, which is crucial for consistency.

`idmap_rid:BUILTIN=ldapserver.com` is a syntax typically used for `idmap_rid` with a specific domain, which is a different ID mapping backend than the general `idmap_ldap` backend for consistent UIDs/GIDs.

The `idmap backend = ldap:ldap://ldapserver.com` directive configures Samba to use the `idmap_ldap` backend, specifying the LDAP server responsible for centralizing and providing UID/GID mappings. This ensures that user and group IDs are consistently resolved across all Samba servers integrated with the specified LDAP directory, preventing inconsistencies when sharing resources.

`ldap passwd sync` is for enabling password synchronization with LDAP, not for configuring the ID mapping backend for UID/GID consistency.