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

     resolvconf -- a framework for managing multiple DNS configurations

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

     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(4) with the argument -a interface[.protocol]
     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 assumes it has a job to do.  In some situations resolvconf
     needs to act as a deterrent to writing to /etc/resolv.conf.  Where this
     file cannot be made immutable or you just need to toggle this behaviour,
     resolvconf can be disabled by adding resolvconf=NO to resolvconf.conf(5).

     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

     resolvconf can mark an interfaces resolv.conf as exclusive.  Only the
     latest exclusive interface is used for processing, otherwise all are.

     When an interface goes down, it should then call resolvconf with -d
     interface.* arguments to delete the resolv.conf file(s) for all the
     protocols on the interface.

     Here are some options for the above commands:-

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

     -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.

     -x      Mark the interface resolv.conf as exclusive when adding, other-
             wise only use the latest exclusive interface.

     resolvconf has some more commands for general usage:-

     -i pattern
             List the interfaces and protocols, 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 and protocols that match it.

     -u      Force resolvconf to update all its 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 commands designed to be used by it's subscribers
     and system startup:-

     -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.

     -R      Echo the command used to restart a service.

     -r service
             If the service is running then restart it.  If the service does
             not exist or is not running then zero is returned, otherwise the
             result of restarting the service.

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

     -V      Same as -v except that only the information configured in
             resolvconf.conf(5) is set.

     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.

     Here are some suggested protocol tags to use for each resolv.conf file
     registered on an interface:-

     dhcp    Dynamic Host Configuration Protocol.  Initial versions of
             resolvconf did not recommend a protocol tag be appended to the
             interface name.  When the protocol is absent, it is assumed to be
             the DHCP protocol.

     ppp     Point-to-Point Protocol.

     ra      IPv6 Router Advertisement.

     dhcp6   Dynamic Host Configuration Protocol, version 6.

     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.

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

     Marks the interface resolv.conf as private.

     Marks the interface resolv.conf as exclusive.

     Backup file of the original resolv.conf.

     Configuration file for resolvconf.

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

     Directory of subscribers which are run after the libc subscriber is run.

     State directory for resolvconf.

     resolver(3), stdin(4), resolv.conf(5), resolvconf.conf(5)

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

     Roy Marples <>

     Please report them to

     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 7.0                     February 23, 2016                    NetBSD 7.0

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