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NAME

rtsold — router solicitation daemon

SYNOPSIS

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. The net.inet6.ip6.forwarding sysctl(8) should be set to zero and the net.inet6.ip6.accept_rtadv and net.inet6.icmp6.rediraccept sysctl(8) should be set to a non-zero value (see also the -F option below).

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 interface ...”.

An interface may be configured at boot to be brought up using rtsol via a hostname.if(5) file. See that man page for more information.

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.

rtsold is able to do some additional configuration for interfaces where more than setting the host's address is needed. When the daemon receives a router advertisement with the “Other Configuration” flag set, the script specified using the -O option is run.

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

The options are as follows:

-1

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

-a

Autoprobe outgoing interfaces. rtsold will try to find any non-loopback, non-point-to-point, IPv6-capable interfaces, and send router solicitation messages on all of them.

-D

Enable more debugging (than that offered by the -d option) including the printing of internal timer information.

-d

Enable debugging.

-F

Automatically set the sysctl(8) variables relating to rtsold (see above). Without this option, rtsold will obey the current sysctl(8) settings.

-f

This option 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.

-O script-name

Specifies a script to handle the Other Configuration flag of the router advertisement (see above). script-name is invoked with a single argument of the receiving interface name, expecting the script will then start a protocol to provide additional configuration. script-name should be specified as the absolute path from root to the script file, and the file itself should be a regular file and owned by the same user running rtsold.

FILES

/var/run/rtsold.dump

Internal state dump file.

EXIT STATUS

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

SEE ALSO

hostname.if(5), netstart(8), 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.

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.