Penguin
Recent Changes
Note: You are viewing an old revision of this page. View the current version.

Acronym for Name Service Switch

The NSS is a glibc mechanism for providing multiple methods of accessing common databases such as the password or hosts database. It is commonly used to provide an interface to both local /etc/passwd (and shadow) files, and a remote authentication mechanism such as NIS or LDAP.

The databases available for configuration within the NSS are:

  • aliases: Mail aliases
  • ethers: Ethernet numbers,
  • group: Groups of users, see section 29.14 Group Database.
  • hosts: Host names and numbers, see section 16.6.2.4 Host Names.
  • netgroup: Network wide list of host and users, see section 29.16 Netgroup Database.
  • networks: Network names and numbers, see section 16.13 Networks Database.
  • protocols: Network protocols, see section 16.6.6 Protocols Database.
  • passwd: User passwords, see section 29.13 User Database.
  • rpc: Remote procedure call names and numbers,
  • services: Network services, see section 16.6.4 The Services Database.
  • shadow: Shadow user passwords

Most of these databases are normally only configured for flatfile access: protocols and services, for example, look up only in /etc/protocols and /etc/services. You could serve these from LDAP, or from a DBM file, or from an SQL database, or so on.

See http://www.delorie.com/gnu/docs/glibc/libc_591.html for more information on the glibc NSS