resolvconf(8) - NetBSD Manual Pages

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RESOLVCONF(8)               System Manager's Manual              RESOLVCONF(8)


NAME

     resolvconf -- a framework for managing multiple DNS configurations


SYNOPSIS

     resolvconf -I
     resolvconf [-m metric] [-p] -a interface <file
     resolvconf [-f] -d interface
     resolvconf -il pattern
     resolvconf -u


DESCRIPTION

     resolvconf manages resolv.conf(5) files from multiple sources, such as
     DHCP and VPN clients.  Traditionally, the host runs just one client and
     that updates /etc/resolv.conf.  More modern systems frequently have wired
     and wireless interfaces and there is no guarantee both are on the same
     network.  With the advent of VPN and other types of networking daemons,
     many things now contend for the contents of /etc/resolv.conf.

     resolvconf solves this by letting the daemon send their resolv.conf(5)
     file to resolvconf via stdin(3) with the argument -a interface instead of
     the filesystem.  resolvconf then updates /etc/resolv.conf as it thinks
     best.  When a local resolver other than libc is installed, such as
     dnsmasq(8) or named(8), then resolvconf will supply files that the
     resolver should be configured to include.

     resolvconf can mark an interfaces resolv.conf as private.  This means
     that the name servers listed in that resolv.conf are only used for
     queries against the domain/search listed in the same file.  This only
     works when a local resolver other than libc is installed.  See
     resolvconf.conf(5) for how to configure resolvconf to use a local name
     server.

     When an interface goes down, it should then call resolvconf with -d
     interface arguments to delete the resolv.conf file for the interface.

     Here are some more options that resolvconf has:-

     -I      Initialise the state directory /var/run/resolvconf.  This only
             needs to be called if the initial system boot sequence does not
             automatically clean it out; for example the state directory is
             moved somewhere other than /var/run.  If used, it should only be
             called once as early in the system boot sequence as possible and
             before resolvconf is used to add interfaces.

     -f      Ignore non existant interfaces.  Only really useful for deleting
             interfaces.

     -i pattern
             List the interfaces, optionally matching pattern, we have
             resolv.conf files for.

     -l pattern
             List the resolv.conf files we have.  If pattern is specified then
             we list the files for the interfaces that match it.

     -m metric
             Set the metric of the interface when adding it, default of 0.
             Lower metrics take precedence.  This affects the default order of
             interfaces when listed.

     -p      Marks the interface resolv.conf as private.

     -u      Force resolvconf to update all it's subscribers.  resolvconf does
             not update the subscribers when adding a resolv.conf that matches
             what it already has for that interface.

     resolvconf also has some options designed to be used by it's sub-
     scribers:-

     -v      Echo variables DOMAINS, SEARCH and NAMESERVERS so that the sub-
             scriber can configure the resolver easily.


INTERFACE ORDERING

     For resolvconf to work effectively, it has to process the resolv.confs
     for the interfaces in the correct order.  resolvconf first processes
     interfaces from the interface_order list, then interfaces without a metic
     and that match the dynamic_order list, then interfaces with a metric in
     order and finally the rest in the operating systems lexical order.  See
     resolvconf.conf(5) for details on these lists.


IMPLEMENTATION NOTES

     If a subscriber has the executable bit then it is executed otherwise it
     is assumed to be a shell script and sourced into the current environment
     in a subshell.  This is done so that subscribers can remain fast, but are
     also not limited to the shell language.

     Portable subscribers should not use anything outside of /bin and /sbin
     because /usr and others may not be available when booting.  Also, it
     would be unwise to assume any shell specific features.


ENVIRONMENT

     IF_METRIC
     If the -m option is not present then we use IF_METRIC for the metric.

     IF_PRIVATE
     Marks the interface resolv.conf as private.


FILES

     /etc/resolvconf.conf
     Configuration file for resolvconf.

     /libexec/resolvconf
     Directory of subscribers which are run every time resolvconf adds,
     deletes or updates.

     /libexec/resolvconf/libc.d
     Directory of subscribers which are run after the libc subscriber is run.

     /var/run/resolvconf
     State directory for resolvconf.


HISTORY

     This implementation of resolvconf is called openresolv and is fully com-
     mand line compatible with Debian's resolvconf, as written by Thomas Hood.


SEE ALSO

     resolv.conf(5), resolvconf.conf(5), resolver(3), stdin(3)


AUTHORS

     Roy Marples <roy@marples.name>


BUGS

     Please report them to http://roy.marples.name/projects/openresolv

     resolvconf does not validate any of the files given to it.

     When running a local resolver other than libc, you will need to configure
     it to include files that resolvconf will generate.  You should consult
     resolvconf.conf(5) for instructions on how to configure your resolver.

NetBSD 6.1.2                     May 13, 2011                     NetBSD 6.1.2