sends router advertisement packets to the
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 described
If there is no configuration file entry for an interface, or if the
configuration file does not exist at all, rtadvd
sets all the parameters to their default values. In particular,
reads all the interface routes from the
routing table and advertises them as on-link prefixes.
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,
adds/deletes the corresponding prefix
to/from its advertising list, respectively. The
option may be used to disable this behavior.
Moreover, if the status of an advertising interface changes,
will start or stop sending router
advertisements according to the latest status.
Basically, hosts MUST NOT send Router Advertisement messages at any time (RFC
4861, Section 6.2.4). However, it would sometimes be useful to allow hosts to
advertise some parameters such as prefix information and link MTU. Thus,
can be invoked if router lifetime is
explicitly set to zero on every advertising interface.
The command line options are:
- Specify an alternate location,
configfile, for the configuration file.
By default, /etc/rtadvd.conf is used.
- Do not daemonize. If this option is specified,
rtadvd will run in the foreground and log to
- Do not add or delete prefixes dynamically. Only statically
configured prefixes, if any, will be advertised.
Upon receipt of signal
will dump the current internal state into
gracefully. In this case,
will transmit router advertisement with
router lifetime 0 to all the interfaces (in accordance with RFC 4861 6.2.5).
- The default configuration file.
utility exits 0 on success,
and >0 if an error occurs.
command first appeared in the WIDE
Hydrangea IPv6 protocol stack kit.
There used to be some text that recommended users not to let
advertise Router Advertisement messages on
an upstream link to avoid undesirable
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 reachability.