RELAYD(8) OpenBSD System Manager's Manual RELAYD(8)NAMErelayd - relay daemon
SYNOPSISrelayd [-dnv] [-D macro=value] [-f file]
DESCRIPTIONrelayd is a daemon to relay and dynamically redirect incoming connections
to a target host. Its main purposes are to run as a load-balancer,
application layer gateway, or transparent proxy. The daemon is able to
monitor groups of hosts for availability, which is determined by checking
for a specific service common to a host group. When availability is
confirmed, layer 3 and/or layer 7 forwarding services are set up by
relayd.
Layer 3 redirection happens at the packet level; to configure it, relayd
communicates with pf(4). To allow relayd to properly set up pf(4) rules,
the following line is required in the filter section of pf.conf(5):
anchor "relayd/*"
Layer 7 relaying happens at the application level and is handled by
relayd itself. Various application level filtering and protocol-specific
load-balancing options are available for relays.
relayd works in terms of the following entities: relays, protocols,
redirections, and tables. A relay represents a layer 7 load-balancing
instance. Each instance translates to a listening TCP or UDP port. A
protocol defines which actions, if any, are taken on the packet payload
as data crosses a relay. A redirection represents a layer 3 load-
balancing instance. Each instance translates to a pf(4) rdr-to rule
being added. A table represents a group of hosts which can be checked
for availability using the same method. Each table contains at least one
host. If a table is used in a layer 3 load-balancing instance, it will
be mapped to a pf(4) table containing only those hosts which are up.
All these entities can be configured in relayd.conf(5), and relayctl(8)
can be used to alter or report on the status of each entity.
The options are as follows:
-D macro=value
Define macro to be set to value on the command line. Overrides
the definition of macro in the configuration file.
-d Do not daemonize. If this option is specified, relayd will run
in the foreground and log to stderr.
-f file
Specify an alternative configuration file. The default is
/etc/relayd.conf.
-n Configtest mode. Only check the configuration file for validity.
-v Produce more verbose output.
FILES
/etc/relayd.conf Default configuration file.
/var/run/relayd.sock UNIX-domain socket used for communication with
relayctl(8).
SEE ALSOrelayd.conf(5), relayctl(8)HISTORY
The relayd program, formerly known as hoststated, first appeared in
OpenBSD 4.1. It was renamed to relayd in OpenBSD 4.3.
AUTHORS
The relayd program was written by Pierre-Yves Ritschard <pyr@openbsd.org>
and Reyk Floeter <reyk@openbsd.org>.
OpenBSD 4.9 May 24, 2010 OpenBSD 4.9