Router solicitation daemon


rtsold [-1Ddfm] -a
rtsold [-1Ddfm] interface ...
rtsol [-Dd] -a
rtsol [-Dd] interface ...        


Perform only one probe. Send Router Solicitation packets until valid Router Advertisement packets arrive from all the interfaces, then exit.
Autoprobe the outgoing interface. The rtsold daemon tries to find a non-loopback, non-point-to-point, IPv6-capable interface. If it finds multiple interfaces, rtsold exits with an error.
Increase the debugging level. Also print internal timer information.
Enable debugging.
Prevent rtsold from becoming a daemon (foreground mode). Warning messages are generated to standard error output, instead of syslog().
Enable mobility support; send probing packets to the default routers that advertised Router Advertisements when the node (re)attached to an interface. Periodically send Router Solicitation on an interface that doesn't support SIOCGIFMEDIA ioctl.
Name of the interface(s) where messages are to be sent.


The rtsold daemon sends 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.

If you use rtsol, probes are transmitted from the interface specified, without becoming a daemon. It behaves the same as:

rtsold -f1 interface

The rtsold daemon sends at most three Router Solicitations on an interface after one of the following events:

  • Just after the rtsold daemon has started.
  • The interface is up after a temporary interface failure. Failures are detected by rtsold by periodically probing the status of the interface. Some network cards and drivers don't allow the extraction of the link state. In these cases, rtsold won't be able to detect a change in the status.
  • Every 60 seconds, if -m is specified and rtsold can't get the interface status. This feature doesn't conform to 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 sends a Router Solicitation, and receives 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 its link-layer address.

When a SIGUSR1 signal is received, rtsold dumps the current internal state into /var/run/rtsold.dump.


The pid of the currently running rtsold.
Dump of the current internal state.

Exit status:

Successful completion.
An error occurred.


Before this utility will work, you need to enable the TCP/IP stack to accept route advertisements, like this:

sysctl -w net.inet6.ip6.accept_rtadv=1

Last modified: 2013-12-21

Got questions about leaving a comment? Get answers from our Disqus FAQ.

comments powered by Disqus