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.
.Lp 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.
.Lp When sending a Router Solicitation on an interface, rtsold includes a Source Link-layer address option if the interface has a link-layer address.
.Lp rtsold manages a per-interface parameter to detect if a separate protocol is needed for configuration parameters other than hosts addresses. At the invocation time, the flag is FALSE, and becomes TRUE when the daemon receives a router advertisement with the OtherConfig flag being set. A script file can be specified to deal with the case (see below). When rtsold start resending router solicitation messages by one of the conditions events, the daemon resets the parameter because the event may indicate a change on the attached link.
Upon receipt of signal SIGUSR1, rtsold will dump the current internal state into /var/run/rtsold.dump.
The options are as follows: