This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles.

For more information about the manual page format, see the manual page for manpages(5).

LWRESD(8)                                           BIND9                                          LWRESD(8)



NAME
       lwresd - lightweight resolver daemon

SYNOPSIS
       lwresd [-C config-file] [-d debug-level] [-f] [-g] [-i pid-file] [-n #cpus] [-P port] [-p port] [-s]
              [-t directory] [-u user] [-v]

DESCRIPTION
       lwresd is the daemon providing name lookup services to clients that use the BIND 9 lightweight
       resolver library. It is essentially a stripped-down, caching-only name server that answers queries
       using the BIND 9 lightweight resolver protocol rather than the DNS protocol.

       lwresd listens for resolver queries on a UDP port on the IPv4 loopback interface, 127.0.0.1. This
       means that lwresd can only be used by processes running on the local machine. By default UDP port
       number 921 is used for lightweight resolver requests and responses.

       Incoming lightweight resolver requests are decoded by the server which then resolves them using the
       DNS protocol. When the DNS lookup completes, lwresd encodes the answers in the lightweight resolver
       format and returns them to the client that made the request.

       If /etc/resolv.conf contains any nameserver entries, lwresd sends recursive DNS queries to those
       servers. This is similar to the use of forwarders in a caching name server. If no nameserver entries
       are present, or if forwarding fails, lwresd resolves the queries autonomously starting at the root
       name servers, using a built-in list of root server hints.

OPTIONS
       -C config-file
           Use config-file as the configuration file instead of the default, /etc/resolv.conf.

       -d debug-level
           Set the daemon's debug level to debug-level. Debugging traces from lwresd become more verbose as
           the debug level increases.

       -f
           Run the server in the foreground (i.e. do not daemonize).

       -g
           Run the server in the foreground and force all logging to stderr.

       -n #cpus
           Create #cpus worker threads to take advantage of multiple CPUs. If not specified, lwresd will try
           to determine the number of CPUs present and create one thread per CPU. If it is unable to
           determine the number of CPUs, a single worker thread will be created.

       -P port
           Listen for lightweight resolver queries on port port. If not specified, the default is port 921.

       -p port
           Send DNS lookups to port port. If not specified, the default is port 53. This provides a way of
           testing the lightweight resolver daemon with a name server that listens for queries on a
           non-standard port number.

       -s
           Write memory usage statistics to stdout on exit.
                  Note: This option is mainly of interest to BIND 9 developers and may be removed or changed
                  in a future release.

       -t directory
           chroot() to directory after processing the command line arguments, but before reading the
           configuration file.
                  Warning: This option should be used in conjunction with the -u option, as chrooting a
                  process running as root doesn't enhance security on most systems; the way chroot() is
                  defined allows a process with root privileges to escape a chroot jail.

       -u user
           setuid() to user after completing privileged operations, such as creating sockets that listen on
           privileged ports.

       -v
           Report the version number and exit.

FILES
       /etc/resolv.conf
           The default configuration file.

       /var/run/lwresd.pid
           The default process-id file.

SEE ALSO
       named(8), lwres(3), resolver(5).

AUTHOR
       Internet Systems Consortium

COPYRIGHT
       Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
       Copyright (C) 2000, 2001 Internet Software Consortium.



BIND9                                           June 30, 2000                                      LWRESD(8)