Hack the Route Start free Open app Services and tunnels
radvd
The router advertisement daemon: which prefixes, flags, lifetimes and DNS servers a router advertises.
/etc/radvd.conf has a block per card: AdvSendAdvert on, how often (MinRtrAdvInterval,
MaxRtrAdvInterval), the router lifetime (AdvDefaultLifetime), the M and O flags (AdvManagedFlag,
AdvOtherConfigFlag), prefix blocks with AdvAutonomous, and RDNSS. A hang-up signal makes it read the file
again and advertise at once.
radvd command usage
radvd [--nodaemon] [-C FILE] [--pidfile FILE] kill -HUP $(cat /run/radvd.pid)
Options
-
--nodaemon - stay in the foreground
-
-C /etc/radvd.conf - the configuration file
-
kill -HUP - read the configuration again
radvd examples
-
cat /etc/radvd.conf - Shows what the router advertises on each card.
-
kill -HUP $(cat /run/radvd.pid) - Makes radvd read its edited file and advertise the change.
Pitfalls
- Any device can run it: a stray radvd makes itself the link's default router. Switches stop that with RA Guard.