RTSOLD(8)

NAME
rtsold - router solicitation daemon

SYNOPSIS
rtsold [-dDfm1] interface ...
rtsold [-dDfm1] -a
rtsol [-dD] interface ...
rtsol [-dD] -a

DESCRIPTION
rtsold is the daemon program to send ICMPv6 Router Solicitation messages on the specified interfaces. If a node (re)attaches to a link, rtsold sends some Router Solicitations on the link destined to the link-local scope all-routers multicast address to discover new routers and to get non link-local addresses.

rtsold should be used on IPv6 hosts (non-router nodes) only.

If you invoke the program as rtsol, it will transmit probes from the specified interface, without becoming a daemon. In other words, rtsol behaves as “ rtsold -f1 interfaces ”.

Specifically, rtsold sends at most 3 Router Solicitations on an interface after one of the following events:

•   Just after invocation of rtsold daemon.
•   The interface is up after a temporary interface failure. rtsold detects such failures by periodically probing to see if the status of the interface is active or not. Note that some network cards and drivers do not allow the extraction of link state. In such cases, rtsold cannot detect the change of the interface status.
•   Every 60 seconds if the -m option is specified and the rtsold daemon cannot get the interface status. This feature does not conform to the IPv6 neighbor discovery specification, but is provided for mobile stations. The default interval for router advertisements, which is on the order of 10 minutes, is slightly long for mobile stations. This feature is provided for such stations so that they can find new routers as soon as possible when they attach to another link.

Once rtsold has sent a Router Solicitation, and has received a valid Router Advertisement, it refrains from sending additional solicitations on that interface, until the next time one of the above events occurs.

When sending a Router Solicitation on an interface, rtsold includes a Source Link-layer address option if the interface has a link-layer address.

Upon receipt of signal SIGUSR1, rtsold will dump the current internal state into /var/run/rtsold.dump.

OPTIONS

-a  Autoprobe outgoing interface. rtsold will try to find a non-loopback, non-point-to-point, IPv6-capable interface. If rtsold finds multiple interfaces, rtsold will exit with error.

-d  Enable debugging.

-D  Enable more debugging including the printing of internal timer information.

-f  -f prevents rtsold from becoming a daemon (foreground mode). Warning messages are generated to standard error instead of syslog(3).

-m  Enable mobility support. If this option is specified, rtsold sends probing packets to default routers that have advertised Router Advertisements when the node (re)attaches to an interface. Moreover, if the option is specified, rtsold periodically sends Router Solicitation on an interface that does not support SIOCGIFMEDIA ioctl.

-1  Perform only one probe. Transmit Router Solicitation packets until at least one valid Router Advertisement packet has arrived on each interface, then exit.

DIAGNOSTICS

FILES
/var/run/rtsold.pid
    the pid of the currently running rtsold.
/var/run/rtsold.dump
    dumps internal state on.

SEE ALSO
rtadvd(8), sysctl(8)

HISTORY
The rtsold command is based on the rtsol command, which first appeared in WIDE/KAME IPv6 protocol stack kit. rtsol is now integrated into rtsold(8).

BUGS
In some operating systems, when a PCMCIA network card is removed and reinserted, the corresponding interface index is changed. However, rtsold assumes such changes will not occur, and always uses the index that it got at invocation. As a result, rtsold may not work if you reinsert a network card. In such a case, rtsold should be killed and restarted.

The IPv6 autoconfiguration specification assumes a single-interface host. You may see kernel error messages if you try to autoconfigure a host with multiple interfaces. Also, it seems contradictory for rtsold to accept multiple interface arguments.