Unix/Linux Go Back    

OpenSolaris 2009.06 - man page for nsswitch.conf (opensolaris section 4)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

nsswitch.conf(4)			   File Formats 			 nsswitch.conf(4)

       nsswitch.conf - configuration file for the name service switch


       The operating system uses a number of databases of information about hosts, ipnodes, users
       (passwd(4), shadow(4), and user_attr(4)), and groups. Data for these can come from a vari-
       ety  of	sources:  hostnames  and host addresses, for example, can be found in /etc/hosts,
       NIS, NIS+, LDAP, DNS or Multicast DNS. Zero or more sources can be used for each database;
       the sources and their lookup order are specified in the /etc/nsswitch.conf file.

       The following databases use the switch file:

	      Database				Used By
       aliases			sendmail(1M)
       auth_attr		getauthnam(3SECDB)
       automount		automount(1M)
       bootparams		rpc.bootparamd(1M)
       ethers			ethers(3SOCKET)
       group			getgrnam(3C)
       hosts			gethostbyname(3NSL),		 getad-
				drinfo(3SOCKET). See  Interaction  with
       ipnodes			Same as hosts.
       netgroup 		innetgr(3C)
       netmasks 		ifconfig(1M)
       networks 		getnetbyname(3SOCKET)
       passwd			getpwnam(3C),  getspnam(3C), getauuser-
				nam(3BSM), getusernam(3SECDB)
       printers 		lp(1), lpstat(1),  cancel(1),  lpr(1B),
				lpq(1B),  lprm(1B),  in.lpd(1M),  lpad-
				min(1M), lpget(1M), lpset(1M)
       prof_attr		getprofnam(3SECDB), getexecprof(3SECDB)
       project			getprojent(3PROJECT),	    getdefault-
				proj(3PROJECT),  inproj(3PROJECT), new-
				task(1), setproject(3PROJECT)
       protocols		getprotobyname(3SOCKET)
       publickey		getpublickey(3NSL), secure_rpc(3NSL)
       rpc			getrpcbyname(3NSL)
       services 		getservbyname(3SOCKET).
				See Interaction with netconfig.
       user_attr		getuserattr(3SECDB)

       The following sources can be used:

	       Source			      Uses

       files			/etc/hosts,	     /etc/passwd,
				/etc/inet/ipnodes,   /etc/shadow,
       nis			NIS(YP)
       nisplus			NIS+
       ldap			LDAP
       ad			Active Directory
       dns			Valid only for hosts and ipnodes.
				Uses  the  Internet  Domain  Name
       mdns			Valid only for hosts and ipnodes.
				Uses the  Multicast  Domain  Name
       compat			Valid  only for passwd and group.
				Implements + and -. See  Interac-
				tion with +/- syntax.
       user			Valid  only  for printers. Imple-
				ments support for ${HOME}/.print-

       Note that /etc/inet/ipnodes is a symbolic link to /etc/hosts.

       There  is  an  entry  in /etc/nsswitch.conf for each database. Typically these entries are
       simple, such as protocols: files  or  networks:	files  nisplus.  However,  when  multiple
       sources	are  specified,  it  is sometimes necessary to define precisely the circumstances
       under which each source is tried. A source can return one of the following codes:

	       Status			      Meaning
       SUCCESS			Requested database entry was found.
       UNAVAIL			Source is not  configured  on  this
				system or internal failure.
       NOTFOUND 		Source responded "no such entry"
       TRYAGAIN 		Source	is  busy or not responding,
				might respond to retries.

       For each status code, two actions are possible:

	       Action			     Meaning
       continue 		Try the next source in the list.
       return			Return now.

       Additionally, for TRYAGAIN only, the following actions are possible:

	       Action			     Meaning
       forever			Retry the current source forever.

       n			Retry the current source  n  more
				times,	where  n  is  an  integer
				between 0 and MAX_INT  (that  is,
				2.14  billion).  After	n retries
				has been exhausted, the  TRYAGAIN
				action	transitions  to continue,
				until a future request receives a
				response,  at  which  time  TRYA-
				GAIN=n is restored.

       The complete syntax of an entry is:

	 <entry>     ::= <database> ":" [<source> [<criteria>]]*
	 <criteria>  ::= "[" <criterion>+ "]"
	 <criterion> ::= <status> "=" <action>
	 <status>    ::= "success" | "notfound" | "unavail" | "tryagain"

       For every status except TRYAGAIN, the action syntax is:

	 <action>    ::= "return"  | "continue"

       For the TRYAGAIN status, the action syntax is:

	 <action>    ::= "return"  | "continue" | "forever" | <n>
	 <n>	     ::= 0...MAX_INT

       Each entry occupies a single line in the file. Lines that are blank, or	that  start  with
       white  space,  are  ignored. Everything on a line following a # character is also ignored;
       the # character can begin anywhere in a line, to be used to begin comments. The <database>
       and  <source>  names are case-sensitive, but <action> and <status> names are case-insensi-

       The library functions contain compiled-in default entries that are used if the appropriate
       entry in nsswitch.conf is absent or syntactically incorrect.

       The  default  criteria  for  DNS  and  the  NIS	server	in "DNS-forwarding mode" is [SUC-
       CESS=return NOTFOUND=continue UNAVAIL=continue TRYAGAIN=3].

       The  default  criteria  for  all  other	sources  is   [SUCCESS=return	NOTFOUND=continue
       UNAVAIL=continue TRYAGAIN=forever].

       The  default,  or explicitly specified, criteria are meaningless following the last source
       in an entry; and they are ignored, since the action is always  to  return  to  the  caller
       irrespective of the status code the source returns.

   Interaction with netconfig
       In  order  to  ensure that they all return consistent results, gethostbyname(3NSL), getad-
       drinfo(3SOCKET), getservbyname(3SOCKET),  and  netdir_getbyname(3NSL)  functions  are  all
       implemented in terms of the same internal library function. This function obtains the sys-
       tem-wide source lookup policy for hosts, ipnodes, and services based on	the  inet  family
       entries in netconfig(4) and uses the switch entries only if the netconfig entries have a -
       (hyphen) in the last column for nametoaddr libraries. See the Notes section in  gethostby-
       name(3NSL) and getservbyname(3SOCKET) for details.

   YP-compatibility Mode
       The NIS+ server can be run in YP-compatibility mode, where it handles NIS (YP) requests as
       well as NIS+ requests. In this case, the clients get much the  same  results  (except  for
       getspnam(3C)) from the nis source as from nisplus; however, nisplus is recommended instead
       of nis.

   Interaction with server in DNS-forwarding Mode
       The NIS (YP) server can be run in DNS-forwarding mode, where it forwards  lookup  requests
       to  DNS	for  host-names  and  -addresses that do not exist in its database. In this case,
       specifying nis as a source for hosts is sufficient to get DNS lookups;  dns  need  not  be
       specified explicitly as a source.

       In  SunOS 5.3 (Solaris 2.3) and compatible versions, the NIS+ server in NIS/YP-compatibil-
       ity mode can also be run in DNS-forwarding mode (see rpc.nisd(1M)). Forwarding  is  effec-
       tive  only  for	requests  originating  from its YP clients; hosts policy on these clients
       should be configured appropriately.

   Interaction with Password Aging
       When password aging is turned on, only a limited set of possible name services are permit-
       ted for the passwd: database in the /etc/nsswitch.conf file:

       passwd:		 files

       passwd:		 files nis

       passwd:		 files nisplus

       passwd:		 files ldap

       passwd:		 compat

       passwd_compat:	 nisplus

       passwd_compat:	 ldap

       You  can add the ad keyword to any of the passwd configurations listed above. However, you
       cannot use the passwd command to change the password of an Active Directory (AD) user.  If
       the  ad	keyword  is  found  in the passwd entry during a password update operation, it is
       ignored. To update the password of an AD user, use the kpasswd(1) command.

       Any other settings causes the passwd(1) command to fail when it	attempts  to  change  the
       password  after	expiration and prevents the user from logging in. These are the only per-
       mitted settings when password aging has been turned on. Otherwise,  you	can  work  around
       incorrect  passwd:  lines by using the -r repository argument to the passwd(1) command and
       using passwd -r repository to override the nsswitch.conf settings  and  specify	in  which
       name service you want to modify your password.

   Interaction with +/- syntax
       Releases  prior	to  SunOS 5.0 did not have the name service switch but did allow the user
       some policy control. In /etc/passwd one could have entries of the form +user (include  the
       specified  user from NIS passwd.byname), -user (exclude the specified user) and + (include
       everything, except excluded users, from NIS passwd.byname). The desired behavior was often
       everything in the file followed by everything in NIS, expressed by a solitary + at the end
       of /etc/passwd. The switch provides an alternative for this case (passwd: files nis)  that
       does not require + entries in /etc/passwd and /etc/shadow (the latter is a new addition to
       SunOS 5.0, see shadow(4)).

       If this is not sufficient, the NIS/YP compatibility source provides full +/- semantics. It
       reads  /etc/passwd  for	getpwnam(3C) functions and /etc/shadow for getspnam(3C) functions
       and, if it finds +/- entries, invokes an appropriate source. By	default,  the  source  is
       nis,  but  this	can  be  overridden  by  specifying nisplus or ldap as the source for the
       pseudo-database passwd_compat.

       Note that in compat mode, for every /etc/passwd entry, there must be a corresponding entry
       in the /etc/shadow file.

       The  NIS/YP  compatibility source also provides full +/- semantics for group; the relevant
       pseudo-database is group_compat.

   Useful Configurations
       The compiled-in default entries for all databases use NIS (YP)  as  the	enterprise  level
       name service and are identical to those in the default configuration of this file:

       passwd:	      files nis

       group:	      files nis

       hosts:	      nis [NOTFOUND=return] files

       ipnodes:       nis [NOTFOUND=return] files

       networks:      nis [NOTFOUND=return] files

       protocols:     nis [NOTFOUND=return] files

       rpc:	      nis [NOTFOUND=return] files

       ethers:	      nis [NOTFOUND=return] files

       netmasks:      nis [NOTFOUND=return] files

       bootparams:    nis [NOTFOUND=return] files

       publickey:     nis [NOTFOUND=return] files

       netgroup:      nis

       automount:     files nis

       aliases:       files nis

       services:      files nis

       printers:      user files nis nisplus

       auth_attr      files nis

       prof_attr      files nis

       project	      files nis

       Note  that  the	files  source  for  the  ipnodes  and  hosts  databases  is identical, as
       /etc/inet/ipnodes is a symbolic link to /etc/hosts. Because other sources for the  ipnodes
       and  hosts  databases  are  different,  do  not remove the ipnodes line from the /etc/nss-
       witch.conf file.

       The policy nis [NOTFOUND=return] files implies: if nis is UNAVAIL, continue on  to  files,
       and  if	nis  returns  NOTFOUND,  return  to  the caller. In other words, treat nis as the
       authoritative source of information and try files only if nis is  down.	This,  and  other
       policies  listed in the default configuration above, are identical to the hard-wired poli-
       cies in SunOS releases prior to 5.0.

       If compatibility with the +/- syntax for passwd and group is required, simply  modify  the
       entries for passwd and group to:

       passwd:	  compat

       group:	  compat

       If NIS+ is the enterprise level name service, the default configuration should be modified
       to use nisplus instead of nis for every database on client machines.  The  file	/etc/nss-
       witch.nisplus  contains a sample configuration that can be copied to /etc/nsswitch.conf to
       set this policy.

       If LDAP is the enterprise level name service, the default configuration should be modified
       to  use	ldap  instead  of  nis	for every database on client machines. The file /etc/nss-
       witch.ldap contains a sample configuration that can be copied to /etc/nsswitch.conf to set
       this policy.

       When using Active Directory, dns is required to perform hosts resolution.

       If  the	use  of +/- syntax is desired in conjunction with nisplus, use the following four

       passwd:		 compat

       passwd_compat:	 nisplus OR ldap

       group:		 compat

       group_compat:	 nisplus OR ldap

       In order to get information from the Internet Domain Name Service for hosts that  are  not
       listed in the enterprise level name service, NIS+ or LDAP, use the following configuration
       and set up the /etc/resolv.conf file (see resolv.conf(4) for more details):

       hosts:	 nisplus dns [NOTFOUND=return] files


       hosts:	 ldap dns [NOTFOUND=return] files

   Enumeration - getXXXent()
       Many of the databases have enumeration functions: passwd has getpwent(), hosts has gethos-
       tent(),	and  so  on.  These were reasonable when the only source was files but often make
       little sense for hierarchically structured sources that contain large numbers of  entries,
       much  less for multiple sources. The interfaces are still provided and the implementations
       strive to provide reasonable results, but the data returned can be incomplete (enumeration
       for  hosts  is  simply not supported by the dns source), inconsistent (if multiple sources
       are used), formatted in an unexpected fashion (for a host with a canonical name and  three
       aliases,  the nisplus source returns four hostents, and they might not be consecutive), or
       very expensive (enumerating a passwd database of 5,000 users is probably a bad idea). Fur-
       thermore,  multiple threads in the same process using the same reentrant enumeration func-
       tion (getXXXent_r() are supported beginning with SunOS 5.3)  share  the	same  enumeration
       position; if they interleave calls, they enumerate disjoint subsets of the same database.

       In  general,  the  use  of the enumeration functions is deprecated. In the case of passwd,
       shadow, and group, it might sometimes be appropriate to use fgetgrent(), fgetpwent(),  and
       fgetspent()  (see  getgrnam(3C),  getpwnam(3C), and getspnam(3C), respectively), which use
       only the files source.

       A source named SSS is implemented by a shared object named nss_SSS.so.1	that  resides  in

       /etc/nsswitch.conf	    Configuration file.

       /usr/lib/nss_compat.so.1     Implements compat source.

       /usr/lib/nss_dns.so.1	    Implements dns source.

       /usr/lib/nss_files.so.1	    Implements files source.

       /usr/lib/nss_mdns.so.1	    Implements mdns source.

       /usr/lib/nss_nis.so.1	    Implements nis source.

       /usr/lib/nss_nisplus.so.1    Implements nisplus source.

       /usr/lib/nss_ldap.so.1	    Implements ldap source.

       /usr/lib/nss_ad.so.1	    Implements ad source.

       /usr/lib/nss_user.so.1	    Implements user source.

       /etc/netconfig		    Configuration  file for netdir(3NSL) functions that redirects
				    hosts/devices policy to the switch.

       /etc/nsswitch.files	    Sample configuration file that uses files only.

       /etc/nsswitch.nis	    Sample configuration file that uses files and nis.

       /etc/nsswitch.nisplus	    Sample configuration file that uses files and nisplus.

       /etc/nsswitch.ldap	    Sample configuration file that uses files and ldap.

       /etc/nsswitch.ad 	    Sample configuration file that uses files and ad.

       /etc/nsswitch.dns	    Sample configuration file that uses files, dns and mdns  (dns
				    and mdns only for hosts).

       kpasswd(1),   ldap(1),	newtask(1),   NIS+(1),	passwd(1),  automount(1M),  ifconfig(1M),
       mdnsd(1M),  rpc.bootparamd(1M),	rpc.nisd(1M),  sendmail(1M),  getauusernam(3BSM),  getgr-
       nam(3C),   getnetgrent(3C),   getpwnam(3C),   getspnam(3C),  gethostbyname(3NSL),  getpub-
       lickey(3NSL), getrpcbyname(3NSL),  netdir(3NSL),  secure_rpc(3NSL),  getprojent(3PROJECT),
       getdefaultproj(3PROJECT),   inproj(3PROJECT),   setproject(3PROJECT),  getauthnam(3SECDB),
       getexecprof(3SECDB),    getprofnam(3SECDB),    getuserattr(3SECDB),    getusernam(3SECDB),
       ethers(3SOCKET),   getaddrinfo(3SOCKET),  getnetbyname(3SOCKET),  getprotobyname(3SOCKET),
       getservbyname(3SOCKET), auth_attr(4), hosts(4), netconfig(4), project(4),  resolv.conf(4),
       user_attr(4), ypfiles(4), ad(5)

       Within  each  process  that  uses nsswitch.conf, the entire file is read only once; if the
       file is later changed, the process continues using the old configuration.

       The use of both nis and nisplus as sources for the same database is  strongly  discouraged
       since  both the name services are expected to store similar information and the lookups on
       the database can yield different results depending on which name service is operational at
       the time of the request. The same applies for using ldap along with nis or nisplus.

       Do not use the ldap and ad keywords together when the Solaris LDAP client uses schema map-
       ping to talk to Active Directory.

       Misspelled names of sources and databases are treated as legitimate names of (most  likely
       nonexistent) sources and databases.

       The following functions do not use the switch: fgetgrent(3C), fgetprojent(3PROJECT), fget-
       pwent(3C), fgetspent(3C), getpw(3C), putpwent(3C), shadow(4).

SunOS 5.11				    6 Nov 2008				 nsswitch.conf(4)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 05:21 AM.