{"abstract": "   EDNS Client Subnet (ECS) lets a recursive resolver send part of a\n   client's network address to authoritative servers, which tailor their\n   answers to it.  A resolver's configuration decides whether it does\n   so, for every client that sends no ECS option of its own.  RFC 7871\n   lets a client opt out.  Asking instead for a shorter prefix requires\n   the client to supply the address those bits are taken from, which a\n   client behind a NAT or a VPN does not know.\n\n   This document defines an opt-in.  A client includes an EDNS(0) option\n   in a query to ask the resolver to forward its address information,\n   and can use that option to limit how many address bits the resolver\n   forwards.  A resolver implementing this document forwards nothing for\n   a client that does not send the option, and one that does not\n   implement it ignores the option.  One resolver address can then serve\n   clients that want tailored answers and those that want their\n   addresses withheld.\n", "ad": null, "expires": "2027-02-21T09:07:21Z", "external_url": "", "group": "/api/v1/group/group/1027/", "id": 160669, "intended_std_level": null, "keywords": "[]", "name": "draft-farrokhi-dnsop-ecs-opt-in", "note": "", "notify": "", "pages": 18, "resource_uri": "/api/v1/doc/document/draft-farrokhi-dnsop-ecs-opt-in/", "rev": "00", "rfc": null, "rfc_number": null, "shepherd": null, "states": ["/api/v1/doc/state/1/", "/api/v1/doc/state/150/"], "std_level": null, "stream": null, "submissions": ["/api/v1/submit/submission/167900/"], "tags": [], "time": "2026-08-20T09:07:21Z", "title": "Client Opt-In Signaling for EDNS Client Subnet", "type": "/api/v1/name/doctypename/draft/", "uploaded_filename": "", "words": null}