From owner-freebsd-net@freebsd.org Sun Nov 24 12:34:59 2019 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 92FCD1AE5D7 for ; Sun, 24 Nov 2019 12:34:59 +0000 (UTC) (envelope-from vas@sibptus.ru) Received: from admin.sibptus.ru (admin.sibptus.ru [IPv6:2001:19f0:5001:21dc::10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 47LV422zm8z40L5 for ; Sun, 24 Nov 2019 12:34:58 +0000 (UTC) (envelope-from vas@sibptus.ru) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sibptus.ru; s=20181118; h=Message-ID:Subject:To:From:Date:In-Reply-To; bh=9dHc/1A1GKSIAn6tp/6oOfnz5vdGe2DERIQ7KqVfs0I=; b=MQeq1XtsMCJGxrVjLm8k1hAEWl qb9rcUANrAQJytugyXCyJWDdU26Z7f4pcUrAd+gNSVMbZGdkbcT4+QGogvKnpuJUJhpvVF+vNjSZn AwUHd9OeCBbtu1z5FbLlTFMoC2Fmy5kLV3DUj/XonYKVH6XQQsqBhzkHBXmQ/Hj/6qtw=; Received: from vas by admin.sibptus.ru with local (Exim 4.92.3 (FreeBSD)) (envelope-from ) id 1iYr6J-0001rB-0W for freebsd-net@freebsd.org; Sun, 24 Nov 2019 19:34:51 +0700 Date: Sun, 24 Nov 2019 19:34:51 +0700 From: Victor Sudakov To: freebsd-net@freebsd.org Subject: Several hosts behind a caching resolver Message-ID: <20191124123451.GA6593@admin.sibptus.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="FL5UXtIhxfXey3p5" Content-Disposition: inline X-PGP-Key: http://admin.sibptus.ru/~vas/ X-PGP-Fingerprint: 10E3 1171 1273 E007 C2E9 3532 0DA4 F259 9B5E C634 User-Agent: Mutt/1.12.2 (2019-09-21) X-Rspamd-Queue-Id: 47LV422zm8z40L5 X-Spamd-Bar: -------- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=sibptus.ru header.s=20181118 header.b=MQeq1Xts; dmarc=pass (policy=none) header.from=sibptus.ru; spf=pass (mx1.freebsd.org: domain of vas@sibptus.ru designates 2001:19f0:5001:21dc::10 as permitted sender) smtp.mailfrom=vas@sibptus.ru X-Spamd-Result: default: False [-8.41 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[sibptus.ru:s=20181118]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.20)[multipart/signed,text/plain]; TO_DN_NONE(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; RCPT_COUNT_ONE(0.00)[1]; IP_SCORE(-3.31)[ip: (-9.85), ipnet: 2001:19f0:5000::/38(-4.93), asn: 20473(-1.71), country: US(-0.05)]; DKIM_TRACE(0.00)[sibptus.ru:+]; DMARC_POLICY_ALLOW(-0.50)[sibptus.ru,none]; SIGNED_PGP(-2.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:20473, ipnet:2001:19f0:5000::/38, country:US]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 24 Nov 2019 12:34:59 -0000 --FL5UXtIhxfXey3p5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Dear Colleagues, Several hosts of the local network use a FreeBSD server with BIND or local-unbound as a caching resolver. Let's call it "Resolver A." Resolver A forwards all queries to another resolver, e.g. 8.8.8.8 or some other, let's call it "Resolver B." Can the operator of Resolver B figure out how many clients there are behind Resolver A, or obtain any other information about the hosts on the said local network (like their operating system etc)? In other words, does Resolver A effectively anonymize the queries, or is some information about the internal network leaking? --=20 Victor Sudakov, VAS4-RIPE, VAS47-RIPN 2:5005/49@fidonet http://vas.tomsk.ru/ --FL5UXtIhxfXey3p5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJd2njqAAoJEA2k8lmbXsY0BO8IALqWilw8iv2Xkg7JKXIzjyRg 9qfDHgXAMyZ7U8FzkUN0/Hb8O270KL6rllYSJLL53Jshj4dqHeG5I1xuN1WSWZBn 0u+LcJsnbM6OGTSU5qL3gS6sXYiT1dTI6bhqzRquOtyQ9GFFjf5TwN4o3wBl0xty ARP53EoMytGEB2B967LrVO+2/Cm7/sI9iiE5oXP7o6nWmKaXLmPLaILIoYmDDTiO zJK/z3rZ65s0zrvo6jLeG5kTY/pv3C8XjnYspB3bI1v4sT0KVtme/k6cH+BSU+X6 CqjHLyXitV5H6nNm8Bpy1wo1KAsu6UkeJrKtaQueo4QkPWPS43Ru/bvrqw8Vwac= =feQx -----END PGP SIGNATURE----- --FL5UXtIhxfXey3p5--