Route Information Options in IPv6 Neighbor Discovery
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The IPv6 Neighbor Discovery (ND) protocol allows nodes to discover neighbors on the same link. Router Advertisement (RA) messages can also convey routing information by including a non-zero (default) Router Lifetime, and/or Route Information Options (RIOs). This document specifies backward-compatible extensions that permit nodes to include RIOs in other IPv6 ND messages to support the discovery of more-specific routes among neighbors on the link.