Design Alternative for Detecting Network Attachment in IPv6 Networks (DNAv6 Design Alternative)

Efficient detection of network attachment in IPv6 needs the following three components: a method for hosts to detect link change in the presence of unmodified (non-DNAv6) routers, a method for the host to query routers on the link to identify the link (Link Identification) and a method for the routers on the link to consistently respond to such a query with minimal delay (Fast RA). Solving the link identification based strictly on RFC 2461 is difficult because of the flexibility offered to routers in terms of prefixes advertised in a router advertisement (RA) message. Similarly, the random delay in responding to router solicitation messages imposed by RFC 2461 makes it difficult to receive an RA quickly. In this memo, a mechanism that requires the hosts to monitor all the prefixes advertised on the link and use it for link identification in the presence of non-DNAv6 routers is presented. A more efficient link-identification mechanism requiring the DNAv6 routers to monitor the link for advertised prefixes to assist the hosts in link identification combined with a fast router advertisement mechanism that selects the order of response for the router deterministically is also presented.