Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
LWRESD(8)                            BIND9                           LWRESD(8)

       lwresd - lightweight resolver daemon

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

       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, 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.

       -C config-file
          Use config-file as the configuration file instead of the default,

       -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

       -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.

          The default configuration file.

          The default process-id file.

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

       Internet Systems Consortium

       Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC")

BIND9                            June 30, 2000                       LWRESD(8)


Want to link to this manual page? Use this URL:

home | help