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RAD(8) System Manager's Manual RAD(8)

radrouter advertisement daemon

rad [-dnv] [-f file] [-s socket]

rad is an IPv6 router advertisement daemon. It periodically sends IPv6 router advertisement messages with prefix and default router information. Clients like slaacd(8) use these to configure IPv6 addresses on network interfaces and set default routes. Additionally it listens for IPv6 router solicitation messages and responds with router advertisements.

To have rad enabled at boot time, use “rcctl enable rad”, which sets


in rc.conf.local(8).

A running rad can be controlled with the ractl(8) utility.

The options are as follows:

Do not daemonize. If this option is specified, rad will run in the foreground and log to .
Specify an alternative configuration file.
Configtest mode. Only check the configuration file for validity.
Use an alternate location for the default control socket.
Produce more verbose output.

Default rad configuration file.
UNIX-domain socket used for communication with ractl(8).

rad.conf(5), ractl(8), slaacd(8)

R. Draves and D. Thaler, Default Router Preferences and More-Specific Routes, RFC 4191, November 2005.

R. Hinden and S. Deering, IP Version 6 Addressing Architecture, RFC 4291, February 2006.

T. Narten, E. Nordmark, W. Simpson, and H. Soliman, Neighbor Discovery for IP version 6 (IPv6), RFC 4861, September 2007.

A. Yourtchenko and L. Colitti, Reducing Energy Consumption of Router Advertisements, RFC 7772, February 2016.

J. Jeong, S. Park, L. Beloeil, and S. Madanapalli, IPv6 Router Advertisement Options for DNS Configuration, RFC 8106, March 2017.

The rad program first appeared in OpenBSD 6.4.

The rad program was written by Florian Obser <>.

November 10, 2019 OpenBSD-6.9