This is nss-pam-ldapd which provides a Name Service Switch (NSS) module that allows your LDAP server to provide user account, group, host name, alias, netgroup, and basically any other information that you would normally get from /etc flat files or NIS. It also provides a Pluggable Authentication Module (PAM) to do identity and authentication management with an LDAP server on unix systems.
This is implemented using thin NSS and PAM modules which delegate to a dedicated service (nslcd) that queries the LDAP server with persistent connections, authentication, attribute translation, etc.
The NSS module was originally a fork of nss_ldap with some structural design improvements. The most important features of nss-pam-ldapd are:
See the documentation section for more details.