[unix-history] / usr / share / man / cat5 / resolver.0



RESOLVER(5)		      1990		      RESOLVER(5)


N\bNA\bAM\bME\bE
     resolver - resolver configuration file

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     /etc/resolv.conf

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     The _\br_\be_\bs_\bo_\bl_\bv_\be_\br is a set of routines in the C library
     (_\br_\be_\bs_\bo_\bl_\bv_\be_\br(3)) that provide access to the Internet Domain
     Name System.  The resolver configuration file contains
     information that is read by the resolver routines the first
     time they are invoked by a process.  The file is designed to
     be human readable and contains a list of keywords with
     values that provide various types of resolver information.

     On a normally configured system this file should not be
     necessary.  The only name server to be queried will be on
     the local machine, the domain name is determined from the
     host name, and the domain search path is constructed from
     the domain name.

     The different configuration options are:

     n\bna\bam\bme\bes\bse\ber\brv\bve\ber\br
	  Internet address (in dot notation) of a name server
	  that the resolver should query.  Up to MAXNS (currently
	  3) name servers may be listed, one per keyword.  If
	  there are multiple servers, the resolver library
	  queries them in the order listed.  If no n\bna\bam\bme\bes\bse\ber\brv\bve\ber\br
	  entries are present, the default is to use the name
	  server on the local machine.	(The algorithm used is to
	  try a name server, and if the query times out, try the
	  next, until out of name servers, then repeat trying all
	  the name servers until a maximum number of retries are
	  made).

     d\bdo\bom\bma\bai\bin\bn
	  Local domain name.  Most queries for names within this
	  domain can use short names relative to the local
	  domain.  If no d\bdo\bom\bma\bai\bin\bn entry is present, the domain is
	  determined from the local host name returned by
	  _\bg_\be_\bt_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be(2); the domain part is taken to be every-
	  thing after the first `.'.  Finally, if the host name
	  does not contain a domain part, the root domain is
	  assumed.

     s\bse\bea\bar\brc\bch\bh
	  Search list for host-name lookup.  The search list is
	  normally determined from the local domain name; by
	  default, it begins with the local domain name, then
	  successive parent domains that have at least two com-
	  ponents in their names.  This may be changed by listing


Printed 7/27/90               June				1


RESOLVER(5)		      1990		      RESOLVER(5)


	  the desired domain search path following the _\bs_\be_\ba_\br_\bc_\bh
	  keyword with spaces or tabs separating the names.  Most
	  resolver queries will be attempted using each component
	  of the search path in turn until a match is found.
	  Note that this process may be slow and will generate a
	  lot of network traffic if the servers for the listed
	  domains are not local, and that queries will time out
	  if no server is available for one of the domains.

	  The search list is currently limited to six domains
	  with a total of 256 characters.

     The _\bd_\bo_\bm_\ba_\bi_\bn and _\bs_\be_\ba_\br_\bc_\bh keywords are mutually exclusive.  If
     more than one instance of these keywords is present, the
     last instance will override.

     The keyword and value must appear on a single line, and the
     keyword (e.g. n\bna\bam\bme\bes\bse\ber\brv\bve\ber\br) must start the line.  The value
     follows the keyword, separated by white space.

F\bFI\bIL\bLE\bES\bS
     /_\be_\bt_\bc/_\br_\be_\bs_\bo_\bl_\bv._\bc_\bo_\bn_\bf

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     gethostbyname(3N), resolver(3), hostname(7), named(8)
     Name Server Operations Guide for BIND


Printed 7/27/90               June				2
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	4	RESOLVER(5) 1990 RESOLVER(5)
	5
	6
	7
	8	N\bNA\bAM\bME\bE
	9	resolver - resolver configuration file
	10
	11	S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
	12	/etc/resolv.conf
	13
	14	D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
	15	The _\br_\be_\bs_\bo_\bl_\bv_\be_\br is a set of routines in the C library
	16	(_\br_\be_\bs_\bo_\bl_\bv_\be_\br(3)) that provide access to the Internet Domain
	17	Name System. The resolver configuration file contains
	18	information that is read by the resolver routines the first
	19	time they are invoked by a process. The file is designed to
	20	be human readable and contains a list of keywords with
	21	values that provide various types of resolver information.
	22
	23	On a normally configured system this file should not be
	24	necessary. The only name server to be queried will be on
	25	the local machine, the domain name is determined from the
	26	host name, and the domain search path is constructed from
	27	the domain name.
	28
	29	The different configuration options are:
	30
	31	n\bna\bam\bme\bes\bse\ber\brv\bve\ber\br
	32	Internet address (in dot notation) of a name server
	33	that the resolver should query. Up to MAXNS (currently
	34	3) name servers may be listed, one per keyword. If
	35	there are multiple servers, the resolver library
	36	queries them in the order listed. If no n\bna\bam\bme\bes\bse\ber\brv\bve\ber\br
	37	entries are present, the default is to use the name
	38	server on the local machine. (The algorithm used is to
	39	try a name server, and if the query times out, try the
	40	next, until out of name servers, then repeat trying all
	41	the name servers until a maximum number of retries are
	42	made).
	43
	44	d\bdo\bom\bma\bai\bin\bn
	45	Local domain name. Most queries for names within this
	46	domain can use short names relative to the local
	47	domain. If no d\bdo\bom\bma\bai\bin\bn entry is present, the domain is
	48	determined from the local host name returned by
	49	_\bg_\be_\bt_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be(2); the domain part is taken to be every-
	50	thing after the first `.'. Finally, if the host name
	51	does not contain a domain part, the root domain is
	52	assumed.
	53
	54	s\bse\bea\bar\brc\bch\bh
	55	Search list for host-name lookup. The search list is
	56	normally determined from the local domain name; by
	57	default, it begins with the local domain name, then
	58	successive parent domains that have at least two com-
	59	ponents in their names. This may be changed by listing
	60
	61
	62
	63	Printed 7/27/90 June 1
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70	RESOLVER(5) 1990 RESOLVER(5)
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74	the desired domain search path following the _\bs_\be_\ba_\br_\bc_\bh
75	keyword with spaces or tabs separating the names. Most
76	resolver queries will be attempted using each component
77	of the search path in turn until a match is found.
78	Note that this process may be slow and will generate a
79	lot of network traffic if the servers for the listed
80	domains are not local, and that queries will time out
81	if no server is available for one of the domains.
82
83	The search list is currently limited to six domains
84	with a total of 256 characters.
85
86	The _\bd_\bo_\bm_\ba_\bi_\bn and _\bs_\be_\ba_\br_\bc_\bh keywords are mutually exclusive. If
87	more than one instance of these keywords is present, the
88	last instance will override.
89
90	The keyword and value must appear on a single line, and the
91	keyword (e.g. n\bna\bam\bme\bes\bse\ber\brv\bve\ber\br) must start the line. The value
92	follows the keyword, separated by white space.
93
94	F\bFI\bIL\bLE\bES\bS
95	/_\be_\bt_\bc/_\br_\be_\bs_\bo_\bl_\bv._\bc_\bo_\bn_\bf
96
97	S\bSE\bEE\bE A\bAL\bLS\bSO\bO
98	gethostbyname(3N), resolver(3), hostname(7), named(8)
99	Name Server Operations Guide for BIND
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