asynchronously synchronise local NSS databases with remote directory services

 Synchronises local NSS caches, such as those served by the
 libnss-cache module, against remote directory services, such as
 LDAP, or prebuild cache files from an HTTP server. This can be
 used alongside the libnss-cache package to keep user account
 information, groups, netgroups, and automounts up to date.
 .
 Use of nsscache and libnss-cache eliminates the need for using a
 cache daemon such as nscd with networked NSS modules such as
 libnss-ldap.