Provided by: resolvconf_1.34ubuntu2_all
resolvconf - manage nameserver information
cat FILE | resolvconf -a INTERFACE
resolvconf -d INTERFACE
Overwrite (-a) or delete (-d) the nameserver information record for
network interface INTERFACE and run the update scripts in
With -u, just run the update scripts.
Normally resolvconf is run only by hook scripts attached to network
interface configurers such as pppd(8) (for ppp interfaces), to DHCP
clients such as dhclient3(8), to ifup(8) and ifdown, and to DNS caches
such as dnsmasq(8) (for the loopback interface). However, the
administrator can also run resolvconf from the command line to add or
delete auxiliary nameserver information.
Nameserver information provided to resolvconf is stored for use by
subscribers to resolvconf’s notification service. Subscribers that
need to know when nameserver information has changed should install a
script in /etc/resolvconf/update.d/ (... or in /etc/resolvconf/update-
libc.d/: see below). For example, DNS caches such as dnsmasq(8) and
pdnsd(8) subscribe to the notification service so that they know
whither to forward queries.
The most important piece of software that subscribes to the
notification service is the set of functions that make up the GNU C
Library resolver(3). When nameserver information is updated the script
/etc/resolvconf/update.d/libc writes a new resolver configuration file
to /etc/resolvconf/run/resolv.conf and then runs the scripts in
/etc/resolvconf/update-libc.d/. To make the resolver use the
dynamically generated resolver configuration file the administrator
should ensure that /etc/resolv.conf is a symbolic link to
/etc/resolvconf/run/resolv.conf. This link is never modified by
/sbin/resolvconf. If you find that /etc/resolv.conf is not being
updated, check to see that the link is intact.
The GNU C Library resolver library isn’t the only resolver library
available. However, any resolver library that reads /etc/resolv.conf
(and most of them do, in order to be compatible with the GNU C Library
resolver) should work with resolvconf.
Subscribers that need to know only when the resolver configuration file
has changed should install a script in /etc/resolvconf/update-libc.d/
rather than in /etc/resolvconf/update.d/. (This is important for
synchronization purposes: scripts in update-libc.d/ are run after
resolv.conf has been updated; the same is not necessarily true of
scripts in update.d/.) Examples of packages that do this are
fetchmail(1) and squid(8).
Hook scripts will find the files containing nameserver information in
the current directory.
Add or overwrite the record for network interface INTERFACE.
When this option is used the information must be provided to
resolvconf on its standard input in the format of the
resolv.conf(5) file. Each line in the file must be terminated
by a newline.
Delete the record for network interface INTERFACE.
The INTERFACE name may not contain spaces, slashes or initial dots,
hyphens or tildes.
Following the addition or deletion of the record, resolvconf runs the
update scripts as described in the CLIENTS section.
-u Just run the update scripts.
This is either a directory where nameserver information can be
stored or a symbolic link to such a directory. Clients should
not make any assumptions about the canonical location of this
directory or the hierarchy that is constructed under it.
Determines the order in which nameserver information records are
processed. See interface-order(5).
File containing basic resolver information. The lines in this
file are included in the resolver configuration file even when
no interfaces are configured.
File to be prepended to the dynamically generated resolver
configuration file. Normally this is just a comment line.
File to be appended to the dynamically generated resolver
configuration file. To append nothing, make this an empty file.
Currently resolvconf does not check the sanity of the information
provided to it.
Written by Thomas Hood <email@example.com>.
Copyright © 2004 Thomas Hood
This is free software; see the source for copying conditions. There is
NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
interface-order(5), resolv.conf(5), resolver(3).