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First draft of resolver(5) man page
This commit is contained in:
Jim Reid
parent
69f2a57302
commit
fa263add26
215
doc/man/bin/resolver.5
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215
doc/man/bin/resolver.5
Normal file
@ -0,0 +1,215 @@
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.\" Copyright (C) @YEARS@ Internet Software Consortium.
|
||||
.\"
|
||||
.\" Permission to use, copy, modify, and distribute this software for any
|
||||
.\" purpose with or without fee is hereby granted, provided that the above
|
||||
.\" copyright notice and this permission notice appear in all copies.
|
||||
.\"
|
||||
.\" THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
|
||||
.\" DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
|
||||
.\" INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
|
||||
.\" FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
|
||||
.\" NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
|
||||
.\" WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||||
.\"
|
||||
.\" $Id: resolver.5,v 1.1 2000/09/03 20:45:58 jim Exp $
|
||||
.\"
|
||||
.Dd Jun 30, 2000
|
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.Dt RESOLVER 5
|
||||
.Os BIND9 9
|
||||
.ds vT BIND9 Programmer's Manual
|
||||
.Sh NAME
|
||||
.Nm resolver
|
||||
.Nd resolver configuration file
|
||||
.Sh SYNOPSIS
|
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.Pa /etc/resolv.conf
|
||||
.Sh DESCRIPTION
|
||||
The
|
||||
.Nm resolver
|
||||
and
|
||||
.Nm "BIND9 lightwreight resolver"
|
||||
are sets of routines in the C library and BIND9 library respectively
|
||||
that provide access to the Internet Domain Name System.
|
||||
The resolver configuration file,
|
||||
.Pa /etc/resolv.conf ,
|
||||
is normally gets read
|
||||
by the resolver and lightweight resolver
|
||||
routines to initialise low-level resolver data structures the first time
|
||||
that a process invokes those routines.
|
||||
The file contains a list of
|
||||
keywords with values that provide various types of
|
||||
information, such as the IP addresses of the servers that should be
|
||||
used when making lookup requests.
|
||||
.Pp
|
||||
Each keyword and value must appear on a single line.
|
||||
The value follows the keyword, separated by white space.
|
||||
The hash character '#' or semi-colon ';' introduce comments.
|
||||
Anything from either of these characters to the end of the line
|
||||
is treated as a comment and ignored.
|
||||
.\" XXXJR - Don't think the next para is relevant. Not every host will run
|
||||
.\" a name server or lightweight resolver. Those that don't will need
|
||||
.\" a resolv.conf so they can send their lookups somewhere sensible.
|
||||
.\".Pp
|
||||
.\"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.
|
||||
.Pp
|
||||
The available configuration directives are:
|
||||
.Bl -tag -width "nameserver"
|
||||
.It Li nameserver
|
||||
Internet address of a name server that the resolver should query.
|
||||
The IP address of the server can be supplied in the usual notation:
|
||||
either in dotted-decimal form for an IPv4 addess or in double colon
|
||||
form described in RFC1884 for an IPv6 address.
|
||||
Up to three nameserver directives can be listed.
|
||||
See
|
||||
.Dv LWRES_CONFMAXNAMESERVERS
|
||||
in
|
||||
.Pa <lwres/lwres.h> .
|
||||
If more than
|
||||
.Dv LWRES_CONFMAXNAMESERVERS
|
||||
nameserver directives are present in the file,
|
||||
only the first three are used.
|
||||
Any others are ignored.
|
||||
.Pp
|
||||
When there are multiple servers, the resolver
|
||||
library queries them in the order listed.
|
||||
If no
|
||||
.Li nameserver
|
||||
entries are present, the default is to attempt to use the name server or
|
||||
lightweight resolver daemon on the local machine.
|
||||
The algorithm used is to try a 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.
|
||||
.It Li domain
|
||||
Local domain name.
|
||||
Most queries for names within this domain can use short names
|
||||
relative to the local domain.
|
||||
When no
|
||||
.Li domain
|
||||
entry is present, the domain is determined from the local host name returned by
|
||||
.Xr gethostname 2 ;
|
||||
the domain part is taken to be everything after the first
|
||||
.Sq \&. .
|
||||
Finally, if the host name does not contain a domain part, the root
|
||||
domain is assumed.
|
||||
.It Li search
|
||||
Search list for host-name lookup.
|
||||
The search list is normally determined from the local domain name;
|
||||
by default, it contains only the local domain name.
|
||||
This may be changed by listing the desired domain search path
|
||||
following the
|
||||
.Li search
|
||||
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.
|
||||
.Pp
|
||||
The search list is currently limited to eight domains
|
||||
with a total of 256 characters.
|
||||
See
|
||||
.Dv LWRES_CONFMAXSEARCH
|
||||
and
|
||||
.Dv LWRES_CONFMAXLINELEN
|
||||
in
|
||||
.Pa lwres/lwres.h .
|
||||
.It Li sortlist
|
||||
Allows addresses returned by gethostbyname to be sorted.
|
||||
A
|
||||
.Li sortlist
|
||||
is specified by IP address netmask pairs.
|
||||
The netmask is optional and defaults to the natural netmask of the net.
|
||||
The IP address and optional network pairs are separated by slashes.
|
||||
Up to 10 pairs may be specified.
|
||||
For example:
|
||||
.Bd -literal -offset indent
|
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sortlist 130.155.160.0/255.255.240.0 130.155.0.0
|
||||
.Ed
|
||||
.It Li options
|
||||
Allows certain internal
|
||||
.Nm resolver
|
||||
variables to be modified.
|
||||
The syntax is
|
||||
.D1 Li options Ar option ...
|
||||
where
|
||||
.Ar option
|
||||
is one of the following:
|
||||
.Bl -tag -width "no_tld_query"
|
||||
.It Li ndots: Ns Ar n
|
||||
sets a threshold for the number of dots which
|
||||
must appear in a name given to
|
||||
.Fn res_query
|
||||
(see
|
||||
.Xr resolver 3 )
|
||||
before an
|
||||
.Em initial absolute query
|
||||
will be made.
|
||||
The default for
|
||||
.Ar n
|
||||
is
|
||||
.Dq 1 ,
|
||||
meaning that if there are
|
||||
.Em any
|
||||
dots in a name, the name will be tried first as an absolute name before any
|
||||
.Em search list
|
||||
elements are appended to it.
|
||||
Acceptable values of
|
||||
.Ar n
|
||||
are between 0 and 255 inclusive.
|
||||
.It debug
|
||||
enables debugging traces for the resolver
|
||||
XXXJR if anything actually looked at
|
||||
.Dv confdata->resdebug .
|
||||
At present the option is just recognised but not used by
|
||||
the BIND9 implementation.
|
||||
.It no_tld_query
|
||||
tells the resolver not to attempt to resolve a
|
||||
top level domain name, i.e. a name containing no dots.
|
||||
Use of this option does not prevent the resolver from obeying the
|
||||
standard
|
||||
.Ar domain
|
||||
and
|
||||
.Ar search
|
||||
rules with the given name.
|
||||
XXXJR At present this option is recognised but is otherwise unused
|
||||
in BIND9.
|
||||
.It missing
|
||||
XXXJR what about the other BIND8 resolver options like rotate and
|
||||
timeout? Shouldn't these be provided for backwards compatibility?
|
||||
.El
|
||||
.El
|
||||
.Pp
|
||||
The
|
||||
.Li domain
|
||||
and
|
||||
.Li search
|
||||
keywords are mutually exclusive.
|
||||
If more than one instance of these keywords is present,
|
||||
the last instance wins.
|
||||
.Sh FILES
|
||||
.Pa /etc/resolv.conf
|
||||
.Pa <lwres/lwres.h>
|
||||
.Sh SEE ALSO
|
||||
.Xr gethostbyname 3 ,
|
||||
.Xr lwres_config 3 ,
|
||||
.Xr lwres 3 ,
|
||||
.Xr resolver 3 ,
|
||||
.Xr hostname 7 ,
|
||||
.Xr lwresd 8 ,
|
||||
.Xr named 8 ,
|
||||
"BIND9 Administrators Manual".
|
||||
.Sh BUGS
|
||||
Unrecognised directives and syntax errors in
|
||||
.Pa /etc/resolv.conf
|
||||
are usually silently ignored, though
|
||||
.Er LWRES_R_FAILURE
|
||||
can be returned by the lightweight resolver functions described in
|
||||
.Xr lwres_config 3
|
||||
which parse this file.
|
||||
215
doc/man/lwres/resolver.5
Normal file
215
doc/man/lwres/resolver.5
Normal file
@ -0,0 +1,215 @@
|
||||
.\" Copyright (C) @YEARS@ Internet Software Consortium.
|
||||
.\"
|
||||
.\" Permission to use, copy, modify, and distribute this software for any
|
||||
.\" purpose with or without fee is hereby granted, provided that the above
|
||||
.\" copyright notice and this permission notice appear in all copies.
|
||||
.\"
|
||||
.\" THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
|
||||
.\" DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
|
||||
.\" INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
|
||||
.\" FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
|
||||
.\" NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
|
||||
.\" WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||||
.\"
|
||||
.\" $Id: resolver.5,v 1.1 2000/09/03 20:45:58 jim Exp $
|
||||
.\"
|
||||
.Dd Jun 30, 2000
|
||||
.Dt RESOLVER 5
|
||||
.Os BIND9 9
|
||||
.ds vT BIND9 Programmer's Manual
|
||||
.Sh NAME
|
||||
.Nm resolver
|
||||
.Nd resolver configuration file
|
||||
.Sh SYNOPSIS
|
||||
.Pa /etc/resolv.conf
|
||||
.Sh DESCRIPTION
|
||||
The
|
||||
.Nm resolver
|
||||
and
|
||||
.Nm "BIND9 lightwreight resolver"
|
||||
are sets of routines in the C library and BIND9 library respectively
|
||||
that provide access to the Internet Domain Name System.
|
||||
The resolver configuration file,
|
||||
.Pa /etc/resolv.conf ,
|
||||
is normally gets read
|
||||
by the resolver and lightweight resolver
|
||||
routines to initialise low-level resolver data structures the first time
|
||||
that a process invokes those routines.
|
||||
The file contains a list of
|
||||
keywords with values that provide various types of
|
||||
information, such as the IP addresses of the servers that should be
|
||||
used when making lookup requests.
|
||||
.Pp
|
||||
Each keyword and value must appear on a single line.
|
||||
The value follows the keyword, separated by white space.
|
||||
The hash character '#' or semi-colon ';' introduce comments.
|
||||
Anything from either of these characters to the end of the line
|
||||
is treated as a comment and ignored.
|
||||
.\" XXXJR - Don't think the next para is relevant. Not every host will run
|
||||
.\" a name server or lightweight resolver. Those that don't will need
|
||||
.\" a resolv.conf so they can send their lookups somewhere sensible.
|
||||
.\".Pp
|
||||
.\"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.
|
||||
.Pp
|
||||
The available configuration directives are:
|
||||
.Bl -tag -width "nameserver"
|
||||
.It Li nameserver
|
||||
Internet address of a name server that the resolver should query.
|
||||
The IP address of the server can be supplied in the usual notation:
|
||||
either in dotted-decimal form for an IPv4 addess or in double colon
|
||||
form described in RFC1884 for an IPv6 address.
|
||||
Up to three nameserver directives can be listed.
|
||||
See
|
||||
.Dv LWRES_CONFMAXNAMESERVERS
|
||||
in
|
||||
.Pa <lwres/lwres.h> .
|
||||
If more than
|
||||
.Dv LWRES_CONFMAXNAMESERVERS
|
||||
nameserver directives are present in the file,
|
||||
only the first three are used.
|
||||
Any others are ignored.
|
||||
.Pp
|
||||
When there are multiple servers, the resolver
|
||||
library queries them in the order listed.
|
||||
If no
|
||||
.Li nameserver
|
||||
entries are present, the default is to attempt to use the name server or
|
||||
lightweight resolver daemon on the local machine.
|
||||
The algorithm used is to try a 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.
|
||||
.It Li domain
|
||||
Local domain name.
|
||||
Most queries for names within this domain can use short names
|
||||
relative to the local domain.
|
||||
When no
|
||||
.Li domain
|
||||
entry is present, the domain is determined from the local host name returned by
|
||||
.Xr gethostname 2 ;
|
||||
the domain part is taken to be everything after the first
|
||||
.Sq \&. .
|
||||
Finally, if the host name does not contain a domain part, the root
|
||||
domain is assumed.
|
||||
.It Li search
|
||||
Search list for host-name lookup.
|
||||
The search list is normally determined from the local domain name;
|
||||
by default, it contains only the local domain name.
|
||||
This may be changed by listing the desired domain search path
|
||||
following the
|
||||
.Li search
|
||||
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.
|
||||
.Pp
|
||||
The search list is currently limited to eight domains
|
||||
with a total of 256 characters.
|
||||
See
|
||||
.Dv LWRES_CONFMAXSEARCH
|
||||
and
|
||||
.Dv LWRES_CONFMAXLINELEN
|
||||
in
|
||||
.Pa lwres/lwres.h .
|
||||
.It Li sortlist
|
||||
Allows addresses returned by gethostbyname to be sorted.
|
||||
A
|
||||
.Li sortlist
|
||||
is specified by IP address netmask pairs.
|
||||
The netmask is optional and defaults to the natural netmask of the net.
|
||||
The IP address and optional network pairs are separated by slashes.
|
||||
Up to 10 pairs may be specified.
|
||||
For example:
|
||||
.Bd -literal -offset indent
|
||||
sortlist 130.155.160.0/255.255.240.0 130.155.0.0
|
||||
.Ed
|
||||
.It Li options
|
||||
Allows certain internal
|
||||
.Nm resolver
|
||||
variables to be modified.
|
||||
The syntax is
|
||||
.D1 Li options Ar option ...
|
||||
where
|
||||
.Ar option
|
||||
is one of the following:
|
||||
.Bl -tag -width "no_tld_query"
|
||||
.It Li ndots: Ns Ar n
|
||||
sets a threshold for the number of dots which
|
||||
must appear in a name given to
|
||||
.Fn res_query
|
||||
(see
|
||||
.Xr resolver 3 )
|
||||
before an
|
||||
.Em initial absolute query
|
||||
will be made.
|
||||
The default for
|
||||
.Ar n
|
||||
is
|
||||
.Dq 1 ,
|
||||
meaning that if there are
|
||||
.Em any
|
||||
dots in a name, the name will be tried first as an absolute name before any
|
||||
.Em search list
|
||||
elements are appended to it.
|
||||
Acceptable values of
|
||||
.Ar n
|
||||
are between 0 and 255 inclusive.
|
||||
.It debug
|
||||
enables debugging traces for the resolver
|
||||
XXXJR if anything actually looked at
|
||||
.Dv confdata->resdebug .
|
||||
At present the option is just recognised but not used by
|
||||
the BIND9 implementation.
|
||||
.It no_tld_query
|
||||
tells the resolver not to attempt to resolve a
|
||||
top level domain name, i.e. a name containing no dots.
|
||||
Use of this option does not prevent the resolver from obeying the
|
||||
standard
|
||||
.Ar domain
|
||||
and
|
||||
.Ar search
|
||||
rules with the given name.
|
||||
XXXJR At present this option is recognised but is otherwise unused
|
||||
in BIND9.
|
||||
.It missing
|
||||
XXXJR what about the other BIND8 resolver options like rotate and
|
||||
timeout? Shouldn't these be provided for backwards compatibility?
|
||||
.El
|
||||
.El
|
||||
.Pp
|
||||
The
|
||||
.Li domain
|
||||
and
|
||||
.Li search
|
||||
keywords are mutually exclusive.
|
||||
If more than one instance of these keywords is present,
|
||||
the last instance wins.
|
||||
.Sh FILES
|
||||
.Pa /etc/resolv.conf
|
||||
.Pa <lwres/lwres.h>
|
||||
.Sh SEE ALSO
|
||||
.Xr gethostbyname 3 ,
|
||||
.Xr lwres_config 3 ,
|
||||
.Xr lwres 3 ,
|
||||
.Xr resolver 3 ,
|
||||
.Xr hostname 7 ,
|
||||
.Xr lwresd 8 ,
|
||||
.Xr named 8 ,
|
||||
"BIND9 Administrators Manual".
|
||||
.Sh BUGS
|
||||
Unrecognised directives and syntax errors in
|
||||
.Pa /etc/resolv.conf
|
||||
are usually silently ignored, though
|
||||
.Er LWRES_R_FAILURE
|
||||
can be returned by the lightweight resolver functions described in
|
||||
.Xr lwres_config 3
|
||||
which parse this file.
|
||||
215
lib/lwres/man/resolver.5
Normal file
215
lib/lwres/man/resolver.5
Normal file
@ -0,0 +1,215 @@
|
||||
.\" Copyright (C) @YEARS@ Internet Software Consortium.
|
||||
.\"
|
||||
.\" Permission to use, copy, modify, and distribute this software for any
|
||||
.\" purpose with or without fee is hereby granted, provided that the above
|
||||
.\" copyright notice and this permission notice appear in all copies.
|
||||
.\"
|
||||
.\" THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
|
||||
.\" DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
|
||||
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
|
||||
.\" INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
|
||||
.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
|
||||
.\" FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
|
||||
.\" NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
|
||||
.\" WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||||
.\"
|
||||
.\" $Id: resolver.5,v 1.1 2000/09/03 20:45:58 jim Exp $
|
||||
.\"
|
||||
.Dd Jun 30, 2000
|
||||
.Dt RESOLVER 5
|
||||
.Os BIND9 9
|
||||
.ds vT BIND9 Programmer's Manual
|
||||
.Sh NAME
|
||||
.Nm resolver
|
||||
.Nd resolver configuration file
|
||||
.Sh SYNOPSIS
|
||||
.Pa /etc/resolv.conf
|
||||
.Sh DESCRIPTION
|
||||
The
|
||||
.Nm resolver
|
||||
and
|
||||
.Nm "BIND9 lightwreight resolver"
|
||||
are sets of routines in the C library and BIND9 library respectively
|
||||
that provide access to the Internet Domain Name System.
|
||||
The resolver configuration file,
|
||||
.Pa /etc/resolv.conf ,
|
||||
is normally gets read
|
||||
by the resolver and lightweight resolver
|
||||
routines to initialise low-level resolver data structures the first time
|
||||
that a process invokes those routines.
|
||||
The file contains a list of
|
||||
keywords with values that provide various types of
|
||||
information, such as the IP addresses of the servers that should be
|
||||
used when making lookup requests.
|
||||
.Pp
|
||||
Each keyword and value must appear on a single line.
|
||||
The value follows the keyword, separated by white space.
|
||||
The hash character '#' or semi-colon ';' introduce comments.
|
||||
Anything from either of these characters to the end of the line
|
||||
is treated as a comment and ignored.
|
||||
.\" XXXJR - Don't think the next para is relevant. Not every host will run
|
||||
.\" a name server or lightweight resolver. Those that don't will need
|
||||
.\" a resolv.conf so they can send their lookups somewhere sensible.
|
||||
.\".Pp
|
||||
.\"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.
|
||||
.Pp
|
||||
The available configuration directives are:
|
||||
.Bl -tag -width "nameserver"
|
||||
.It Li nameserver
|
||||
Internet address of a name server that the resolver should query.
|
||||
The IP address of the server can be supplied in the usual notation:
|
||||
either in dotted-decimal form for an IPv4 addess or in double colon
|
||||
form described in RFC1884 for an IPv6 address.
|
||||
Up to three nameserver directives can be listed.
|
||||
See
|
||||
.Dv LWRES_CONFMAXNAMESERVERS
|
||||
in
|
||||
.Pa <lwres/lwres.h> .
|
||||
If more than
|
||||
.Dv LWRES_CONFMAXNAMESERVERS
|
||||
nameserver directives are present in the file,
|
||||
only the first three are used.
|
||||
Any others are ignored.
|
||||
.Pp
|
||||
When there are multiple servers, the resolver
|
||||
library queries them in the order listed.
|
||||
If no
|
||||
.Li nameserver
|
||||
entries are present, the default is to attempt to use the name server or
|
||||
lightweight resolver daemon on the local machine.
|
||||
The algorithm used is to try a 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.
|
||||
.It Li domain
|
||||
Local domain name.
|
||||
Most queries for names within this domain can use short names
|
||||
relative to the local domain.
|
||||
When no
|
||||
.Li domain
|
||||
entry is present, the domain is determined from the local host name returned by
|
||||
.Xr gethostname 2 ;
|
||||
the domain part is taken to be everything after the first
|
||||
.Sq \&. .
|
||||
Finally, if the host name does not contain a domain part, the root
|
||||
domain is assumed.
|
||||
.It Li search
|
||||
Search list for host-name lookup.
|
||||
The search list is normally determined from the local domain name;
|
||||
by default, it contains only the local domain name.
|
||||
This may be changed by listing the desired domain search path
|
||||
following the
|
||||
.Li search
|
||||
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.
|
||||
.Pp
|
||||
The search list is currently limited to eight domains
|
||||
with a total of 256 characters.
|
||||
See
|
||||
.Dv LWRES_CONFMAXSEARCH
|
||||
and
|
||||
.Dv LWRES_CONFMAXLINELEN
|
||||
in
|
||||
.Pa lwres/lwres.h .
|
||||
.It Li sortlist
|
||||
Allows addresses returned by gethostbyname to be sorted.
|
||||
A
|
||||
.Li sortlist
|
||||
is specified by IP address netmask pairs.
|
||||
The netmask is optional and defaults to the natural netmask of the net.
|
||||
The IP address and optional network pairs are separated by slashes.
|
||||
Up to 10 pairs may be specified.
|
||||
For example:
|
||||
.Bd -literal -offset indent
|
||||
sortlist 130.155.160.0/255.255.240.0 130.155.0.0
|
||||
.Ed
|
||||
.It Li options
|
||||
Allows certain internal
|
||||
.Nm resolver
|
||||
variables to be modified.
|
||||
The syntax is
|
||||
.D1 Li options Ar option ...
|
||||
where
|
||||
.Ar option
|
||||
is one of the following:
|
||||
.Bl -tag -width "no_tld_query"
|
||||
.It Li ndots: Ns Ar n
|
||||
sets a threshold for the number of dots which
|
||||
must appear in a name given to
|
||||
.Fn res_query
|
||||
(see
|
||||
.Xr resolver 3 )
|
||||
before an
|
||||
.Em initial absolute query
|
||||
will be made.
|
||||
The default for
|
||||
.Ar n
|
||||
is
|
||||
.Dq 1 ,
|
||||
meaning that if there are
|
||||
.Em any
|
||||
dots in a name, the name will be tried first as an absolute name before any
|
||||
.Em search list
|
||||
elements are appended to it.
|
||||
Acceptable values of
|
||||
.Ar n
|
||||
are between 0 and 255 inclusive.
|
||||
.It debug
|
||||
enables debugging traces for the resolver
|
||||
XXXJR if anything actually looked at
|
||||
.Dv confdata->resdebug .
|
||||
At present the option is just recognised but not used by
|
||||
the BIND9 implementation.
|
||||
.It no_tld_query
|
||||
tells the resolver not to attempt to resolve a
|
||||
top level domain name, i.e. a name containing no dots.
|
||||
Use of this option does not prevent the resolver from obeying the
|
||||
standard
|
||||
.Ar domain
|
||||
and
|
||||
.Ar search
|
||||
rules with the given name.
|
||||
XXXJR At present this option is recognised but is otherwise unused
|
||||
in BIND9.
|
||||
.It missing
|
||||
XXXJR what about the other BIND8 resolver options like rotate and
|
||||
timeout? Shouldn't these be provided for backwards compatibility?
|
||||
.El
|
||||
.El
|
||||
.Pp
|
||||
The
|
||||
.Li domain
|
||||
and
|
||||
.Li search
|
||||
keywords are mutually exclusive.
|
||||
If more than one instance of these keywords is present,
|
||||
the last instance wins.
|
||||
.Sh FILES
|
||||
.Pa /etc/resolv.conf
|
||||
.Pa <lwres/lwres.h>
|
||||
.Sh SEE ALSO
|
||||
.Xr gethostbyname 3 ,
|
||||
.Xr lwres_config 3 ,
|
||||
.Xr lwres 3 ,
|
||||
.Xr resolver 3 ,
|
||||
.Xr hostname 7 ,
|
||||
.Xr lwresd 8 ,
|
||||
.Xr named 8 ,
|
||||
"BIND9 Administrators Manual".
|
||||
.Sh BUGS
|
||||
Unrecognised directives and syntax errors in
|
||||
.Pa /etc/resolv.conf
|
||||
are usually silently ignored, though
|
||||
.Er LWRES_R_FAILURE
|
||||
can be returned by the lightweight resolver functions described in
|
||||
.Xr lwres_config 3
|
||||
which parse this file.
|
||||
Loading…
x
Reference in New Issue
Block a user