Using Router Advertisements to Signal the Availability of DHCPv6 Prefix Delegation to Clients
RFC 9762, “Using Router Advertisements to Signal the Availability of DHCPv6 Prefix Delegation to Clients”, is a Proposed Standard document published in June 2025 by L. Colitti, J. Linkova, X. Ma, D. Lamparter. It updates RFC 4861, RFC 4862. The canonical text is published by the RFC Editor.
Abstract
This document defines the P flag in the Prefix Information Option (PIO) of IPv6 Router Advertisements (RAs). The flag is used to indicate that the network prefers that clients use the deployment model in RFC 9663 instead of using individual addresses in the on-link prefix assigned using Stateless Address Autoconfiguration (SLAAC) or DHCPv6 address assignment.
This document updates RFC 4862 to indicate that the Autonomous flag in a PIO needs to be ignored if the PIO has the P flag set. It also updates RFC 4861 to specify that the P flag indicates DHCPv6 prefix delegation support for clients.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 9762 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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