One of the benefits of IPv6 is stateless autoconfiguration, which allows a user to plug a device on a network and instantly get connected. This feature is accomplished using an IPv6 router that advertises its subnet-prefix, which in turn is used by laptops, smartphones, or any device to configure its own IPv6 address automatically without human intervention.

But as with all things that offer convenience, there's a downside to this feature, especially when there's a rogue IPv6 router performing router advertisement (RA) on the network. This rouge router could be any PC innocently advertising its own subnet-prefix or intentionally deployed for the purpose of performing malicious activity.

The KAME Project has designed a tool called rafixd to detect rouge RAs on the network. You can download it here. You may also want to note that SolidWall™, the firewall appliance of InfoWeapons, has its own mechanism to detect rogue RAs and notify network administrators of its existence. You may request for a free trial here. To learn more about rogue IPv6 RAs, click here.