nsswitch.conf(5) File Formats Manual nsswitch.conf(5) (NAME) nsswitch.conf - (Name Service Switch) (DESCRIPTION) (NSS Name Service Switch) /etc/nsswitch.conf C . . (ASCII) (tab) . . . C : aliases getaliasent(3) . ethers (Ethernet). group getgrent(3) . hosts gethostbyname(3) . initgroups getgrouplist(3) . netgroup . C glibc 2.1 netgroup NIS . networks getnetent(3) . passwd getpwent(3) . protocols getprotoent(3) . publickey Secure_RPC NFS NIS+ . rpc (RPC) getrpcbyname(3) . services getservent(3) . shadow getspnam(3) . C . . sudo(8) sudoers . / (subordinate user/group IDs) subid . subuid(5) subgid(5) . /etc/nsswitch.conf : passwd: compat group: compat shadow: compat hosts: dns [!UNAVAIL=return] files networks: nis [NOTFOUND=return] files ethers: nis [NOTFOUND=return] files protocols: nis [NOTFOUND=return] files rpc: nis [NOTFOUND=return] files services: nis [NOTFOUND=return] files . : o "files" "db" "nis". . o "[NOTFOUND=return]". . /lib/libnss_SERVICE.so.X SERVICE . "files" "db" "nis" "nisplus" . hosts "dns" . passwd group shadow "compat" ( (compat) ). X glibc 2.0 1 glibc 2.1 2 . "hesiod" "ldap" "winbind" "wins" . (action) . . : [STATUS=ACTION] [!STATUS=ACTION] : STATUS => success | notfound | unavail | tryagain ACTION => return | continue | merge ! . . STATUS : success . "return" . notfound . "continue" . unavail . . "continue" . tryagain . . "continue" . ACTION : return . . group notfound initgroups . continue . merge [SUCCESS=merge] . . ( GID ) . glibc 2.24. getgrent(3) () . (compat) NSS "compat" "files" (netgroups) . : passwd shadow: +user user NIS passwd/shadow. +@netgroup netgroup . -user user NIS passwd/shadow. -@netgroup netgroup . + NIS passwd/shadow . group: +group group NIS group. -group group NIS group. + NIS group . "nis" NSS "compat" passwd_compat group_compat shadow_compat . (FILES) SERVICE libnss_SERVICE.so.X /lib . /etc/nsswitch.conf NSS. /lib/libnss_compat.so.X "compat" . /lib/libnss_db.so.X "db" . /lib/libnss_dns.so.X "dns" . /lib/libnss_files.so.X "files" . /lib/libnss_hesiod.so.X "hesiod" . /lib/libnss_nis.so.X "nis" . /lib/libnss_nisplus.so.X "nisplus" . "files" : aliases /etc/aliases ethers /etc/ethers group /etc/group hosts /etc/hosts initgroups /etc/group netgroup /etc/netgroup networks /etc/networks passwd /etc/passwd protocols /etc/protocols publickey /etc/publickey rpc /etc/rpc services /etc/services shadow /etc/shadow (NOTES) glibc 2.33 nsswitch.conf . . . ( /etc/passwd). (NIS Network Information Service) (DNS Domain Name Service) C . (Name Service Switch) Sun Microsystems C Solaris 2 . (SEE ALSO) getent(1), nss(5) Linux man-pages 6.19 2026-02-08 nsswitch.conf(5)