RTADVD(8) BSD System Manager's Manual RTADVD(8)
NAME
rtadvd -- router advertisement daemon
SYNOPSIS
rtadvd [-dDfMRs] [-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 peri-odically, periodically,
odically, as well as in response to router solicitation messages sent by end hosts.
Router advertisements can be configured on a per-interface basis, as described in rtadvd.conf(5).
If there is no configuration file entry for an interface, or if the configuration file does not exist
altogether, 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 direct 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 allow hosts to advertise some parameters such as prefix infor-mation information
mation and link MTU. Thus, rtadvd can be invoked if router lifetime is explicitly set zero on every
advertising interface.
The command line options are:
-c Specify an alternate location, configfile, for the configuration file. By default,
/etc/rtadvd.conf is used.
-d Print debugging information.
-D Even more debugging information is printed.
-f Foreground mode (useful when debugging).
-M Specify an interface to join the all-routers site-local multicast group. By default, rtadvd
tries to join the first advertising interface appeared in the command line. This option has
meaning only with the -R option, which enables routing renumbering protocol support.
-R Accept router renumbering requests. If you enable it, certain IPsec setup is suggested for
security reasons. On KAME-based systems, rrenumd(8) generates router renumbering request pack-ets. packets.
ets. This option is currently disabled, and is ignored by rtadvd with a warning message.
-s Do not add or delete prefixes dynamically. Only statically configured prefixes, if any, will
be advertised.
Upon receipt of signal SIGUSR1, rtadvd will dump the current internal state into /var/run/rtadvd.dump.
Use SIGTERM to kill rtadvd gracefully. In this case, rtadvd will transmit router advertisement with
router lifetime 0 to all the interfaces (in accordance with RFC2461 6.2.5).
DIAGNOSTICS
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.
/var/run/rtadvd.dump in which rtadvd dumps its internal state.
SEE ALSO
rtadvd.conf(5), rrenumd(8), rtsol(8)
HISTORY
The rtadvd command first appeared in WIDE Hydrangea IPv6 protocol stack kit.
CAVEAT
There used to be some text that recommended users not to let rtadvd advertise Router Advertisement mes-sages messages
sages on an upstream link to avoid undesirable icmp6(4) redirect messages. However, based on the later
discussion in the IETF ipng working group, all routers should rather advertise the messages regardless
of the network topology, in order to ensure reachability.
BSD May 17, 1998 BSD
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