rdisc6

Shows what the devices on a link are told: the router lifetime (0: not a default router), the M and O flags (stateful and stateless DHCPv6), each prefix with its autonomous flag and lifetimes, the MTU, and options such as RDNSS (DNS servers). Every router that answers is listed, which is how a second, rogue advertiser shows up.

rdisc6 command usage

rdisc6 [-1] CARD

Options

-1

stop after the first answer

eth0

the card to solicit on

rdisc6 examples

rdisc6 -1 eth0

Asks the link's routers to advertise now, and prints the first answer.

Pitfalls

• The source of each answer is a link-local address: compare it with ip -6 route show default to see which router a device uses.

Run it on real machines