Duplicate Address Detection Algorithm

To ensure that all configured addresses are likely to be unique on a given link, nodes run a duplicate address detection algorithm on addresses before assigning them to an interface. The duplicate address detection algorithm is performed on all addresses, independent of whether they are obtained by stateless or stateful autoconfiguration.

The autoconfiguration process specified in this document applies only to hosts and not routers. Because host autoconfiguration uses information advertised by routers, routers need to be configured by some other means. However, it is expected that routers will generate link-local addresses using the mechanism described in this document. In addition, routers are expected to pass successfully the duplicate address detection procedure on all addresses, prior to assigning them to an interface.