NAME¶lwresd - lightweight resolver daemon
lwresd [-c config-file] [-C config-file] [-d debug-level] [-f] [-g] [-i pid-file] [-m flag] [-n #cpus] [-P port] [-p port] [-s] [-t directory] [-u user] [-v] [-4] [-6]
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.
This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.
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(2) is defined allows a process with root privileges to escape a chroot jail.
SEE ALSO¶named(8), lwres(3), resolver(5).
AUTHOR¶Internet Systems Consortium, Inc.
COPYRIGHT¶Copyright © 2004, 2005, 2007-2009, 2014, 2015 Internet Systems Consortium, Inc. ("ISC")
Copyright © 2000, 2001 Internet Software Consortium.