RTADVD(8)               OpenBSD System Manager's Manual              RTADVD(8)

NAME
     rtadvd - router advertisement daemon

SYNOPSIS
     rtadvd [-dMRs] [-c configfile] interface ...

DESCRIPTION
     rtadvd sends router advertisement packets to the specified interfaces.

     The program will daemonize itself on invocation.  It will then send
     router advertisement packets periodically, as well as in response to
     router solicitation messages sent by end hosts.

     Router advertisements can be configured on a per-interface basis, as de-
     scribed in rtadvd.conf(5).

     If there is no configuration file entry for an interface, or if the con-
     figuration file does not exist at all, rtadvd sets all the parameters to
     their default values.  In particular, rtadvd reads all the interface
     routes from the routing table and advertises them as on-link prefixes.

     rtadvd also watches the routing table.  By default, if an interface di-
     rect route is added/deleted on an advertising interface and no static
     prefixes are specified by the configuration file, rtadvd adds/deletes the
     corresponding prefix to/from its advertising list, respectively.  The -s
     option may be used to disable this behavior.  Moreover, if the status of
     an advertising interface changes, rtadvd will start or stop sending
     router advertisements according to the latest status.

     Basically, hosts MUST NOT send Router Advertisement messages at any time
     (RFC 2461, Section 6.2.3).  However, it would sometimes be useful to al-
     low hosts to advertise some parameters such as prefix information and
     link MTU.  Thus, rtadvd can be invoked if router lifetime is explicitly
     set to zero on every advertising interface.

     The command line options are:

     -c configfile
             Specify an alternate location, configfile, for the configuration
             file.  By default, /etc/rtadvd.conf is used.

     -d      Do not daemonize.  If this option is specified, rtadvd will run
             in the foreground and log to stderr.

     -M      Specify an interface to join the all-routers site-local multicast
             group.  By default, rtadvd tries to join the first advertising
             interface appearing on the command line.  This option has meaning
             only with the -R option, which enables routing renumbering proto-
             col support.

     -R      Accept router renumbering requests.  If you enable it, an
             ipsec(4) setup is suggested for security reasons.  This option is
             currently disabled, and is ignored by rtadvd with a warning mes-
             sage.

     -s      Do not add or delete prefixes dynamically.  Only statically con-
             figured prefixes, if any, will be advertised.

     Upon receipt of signal SIGUSR1, rtadvd will dump the current internal
     state into syslog(3).

     Use SIGTERM to kill rtadvd gracefully.  In this case, rtadvd will trans-
     mit router advertisement with router lifetime 0 to all the interfaces (in
     accordance with RFC 2461 6.2.5).

     The rtadvd utility exits 0 on success, and >0 if an error occurs.

FILES
     /etc/rtadvd.conf       The default configuration file.
     /var/run/rtadvd.pid    Contains the PID of the currently running rtadvd.

SEE ALSO
     rtadvd.conf(5), rtsol(8), syslogd(8)

HISTORY
     The rtadvd command first appeared in the WIDE Hydrangea IPv6 protocol
     stack kit.

BUGS
     There used to be some text that recommended users not to let rtadvd ad-
     vertise Router Advertisement messages on an upstream link to avoid unde-
     sirable icmp6(4) redirect messages.  However, based on later discussion
     in the IETF IPng working group, all routers should rather advertise the
     messages regardless of the network topology, in order to ensure reacha-
     bility.

OpenBSD 4.7                      June 9, 2008                                2
