Name Service Switch

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The Name Service Switch (NSS) is an interface of

nsswitch.conf

A

passwd:     files ldap
shadow:     files
group:      files ldap

hosts:      dns nis files

ethers:     files nis
netmasks:   files nis
networks:   files nis
protocols:  files nis
rpc:        files nis
services:   files nis

automount:  files
aliases:    files

Earlier Unix-like systems either accessed only local files or had hard-coded rules for accessing files or network-stored databases. Ultrix was a notable exception with its nearly identical functionality of the NSS configuration file in /etc/svc.conf.

Solaris' compliance with SVR4, which Sun Microsystems and

Sun engineers Thomas Maslen and Sanjay Dani were the first to design and implement the Name Service Switch. They fulfilled Solaris requirements with the nsswitch.conf file specification and the implementation choice to load database access modules as dynamically loaded libraries, which Sun was also the first to introduce.

Sun engineers' original design of the configuration file and runtime loading of name service back-end libraries has withstood the test of time as operating systems have evolved and new name services are introduced. Over the years, programmers ported the NSS configuration file with nearly identical implementations to many other operating systems including

See also

• BSD Authentication
• Group (database)
• Name server
• Pluggable Authentication Modules

References

External links

• nsswitch.conf(5): name-service switch configuration file – NetBSD File Formats Manual
• Name Service Switch implementation in the GNU C Library
• Another NSS module supporting LDAP: nss-ldapd
• NSS module supporting AFS: nss_afs