From owner-freebsd-net@freebsd.org Sun Mar 15 21:31:27 2020 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 AFD68279885 for ; Sun, 15 Mar 2020 21:31:27 +0000 (UTC) (envelope-from jbe-mlist@magnetkern.de) Received: from sapphire.magnetkern.de (sapphire.magnetkern.de [185.228.139.199]) by mx1.freebsd.org (Postfix) with ESMTP id 48gXgK6rn6z3x6N for ; Sun, 15 Mar 2020 21:31:25 +0000 (UTC) (envelope-from jbe-mlist@magnetkern.de) Received: from titanium (p5DD45F4F.dip0.t-ipconnect.de [93.212.95.79]) by sapphire.magnetkern.de (Postfix) with ESMTPSA id 0097C4107 for ; Sun, 15 Mar 2020 21:31:13 +0000 (UTC) Date: Sun, 15 Mar 2020 22:31:13 +0100 From: Jan Behrens To: freebsd-net@freebsd.org Subject: Re: ifconfig prefer_source and IPv6 privacy extensions Message-Id: <20200315223113.d93045f587faa995795b4bae@magnetkern.de> In-Reply-To: <20200313233752.43d6fc44f51a60acbe4a9bb8@magnetkern.de> References: <20200313202833.cbbe8d1679ac0fd7a80788e1@magnetkern.de> <20200314.045143.1650553685773092770.hrs@FreeBSD.org> <20200313233752.43d6fc44f51a60acbe4a9bb8@magnetkern.de> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; amd64-portbld-freebsd12.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 48gXgK6rn6z3x6N X-Spamd-Bar: ++ Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of jbe-mlist@magnetkern.de designates 185.228.139.199 as permitted sender) smtp.mailfrom=jbe-mlist@magnetkern.de X-Spamd-Result: default: False [2.80 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-net@freebsd.org]; TO_DN_NONE(0.00)[]; NEURAL_SPAM_MEDIUM(0.98)[0.980,0]; RCPT_COUNT_ONE(0.00)[1]; DMARC_NA(0.00)[magnetkern.de]; MV_CASE(0.50)[]; NEURAL_SPAM_LONG(0.97)[0.975,0]; IP_SCORE(0.54)[ipnet: 185.228.136.0/22(3.34), asn: 197540(-0.60), country: DE(-0.02)]; RCVD_NO_TLS_LAST(0.10)[]; RECEIVED_SPAMHAUS_PBL(0.00)[79.95.212.93.khpj7ygk5idzvmvt5x4ziurxhy.zen.dq.spamhaus.net : 127.0.0.10]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:197540, ipnet:185.228.136.0/22, country:DE]; MID_RHS_MATCH_FROM(0.00)[]; FROM_EQ_ENVFROM(0.00)[] 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, 15 Mar 2020 21:31:27 -0000 On Fri, 13 Mar 2020 23:37:52 +0100 Jan Behrens wrote: > On Sat, 14 Mar 2020 04:51:43 +0900 (JST) > Hiroki Sato wrote: > > > Jan Behrens wrote > > in <20200313202833.cbbe8d1679ac0fd7a80788e1@magnetkern.de>: > > > > jb> Is it intended that "net.inet6.ip6.prefer_tempaddr" takes precedence > > jb> over "prefer_source"? If yes, why? > > > > Yes, and the reason is that RFC 6724 specifies that behavior. > > [...] > > > If prefer_source takes precedence, the tempaddr will nerver be used. > > That depends on how "prefer_source" competes with other rules for > source address selection. > > [...] > > Moreover, preferring temporary addresses over addresses marked with > "prefer_source" doesn't seem to make much sense (even if the RFC would > demand it). This is because it doesn't seem to make much sense to mark > a temporary address as preferred. Does anyone know a (real life) example where "prefer_source" has any useful effect (given FreeBSD's current behavior) if privacy extensions are enabled? > That assumed, the current behavior of FreeBSD effectivly renders > "prefer_source" useless if net.inet6.ip6.prefer_tempaddr=1. I would propose to set "prefer_source"'s precedence just one level higher than net.inet6.ip6.prefer_tempaddr. -- Jan > > > > > -- Hiroki > > Regards, > Jan Behrens