4.3BSD-Reno/share/man/cat5/resolver.0

RESOLVER(5)		      1990		      RESOLVER(5)



NNAAMMEE
     resolver - resolver configuration file

SSYYNNOOPPSSIISS
     /etc/resolv.conf

DDEESSCCRRIIPPTTIIOONN
     The _r_e_s_o_l_v_e_r is a set of routines in the C library
     (_r_e_s_o_l_v_e_r(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:

     nnaammeesseerrvveerr
	  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 nnaammeesseerrvveerr
	  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).

     ddoommaaiinn
	  Local domain name.  Most queries for names within this
	  domain can use short names relative to the local
	  domain.  If no ddoommaaiinn entry is present, the domain is
	  determined from the local host name returned by
	  _g_e_t_h_o_s_t_n_a_m_e(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.

     sseeaarrcchh
	  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 _s_e_a_r_c_h
	  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 _d_o_m_a_i_n and _s_e_a_r_c_h 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. nnaammeesseerrvveerr) must start the line.  The value
     follows the keyword, separated by white space.

FFIILLEESS
     /_e_t_c/_r_e_s_o_l_v._c_o_n_f

SSEEEE AALLSSOO
     gethostbyname(3N), resolver(3), hostname(7), named(8)
     Name Server Operations Guide for BIND





























Printed 7/27/90               June				2