From owner-freebsd-net@freebsd.org Wed Jan 11 15:51:39 2017 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 540BBCAB3E6 for ; Wed, 11 Jan 2017 15:51:39 +0000 (UTC) (envelope-from hrs@FreeBSD.org) Received: from mail.allbsd.org (gatekeeper.allbsd.org [IPv6:2001:2f0:104:e001::32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.allbsd.org", Issuer "RapidSSL SHA256 CA - G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D78311FD5 for ; Wed, 11 Jan 2017 15:51:38 +0000 (UTC) (envelope-from hrs@FreeBSD.org) Received: from mail-d.allbsd.org (p2027-ipbf1605funabasi.chiba.ocn.ne.jp [123.225.191.27]) (authenticated bits=56) by mail.allbsd.org (8.15.2/8.15.2) with ESMTPSA id v0BFp5ch055069 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) (Client CN "/OU=GT07882699/OU=See+20www.rapidssl.com/resources/cps+20+28c+2915/OU=Domain+20Control+20Validated+20-+20RapidSSL+28R+29/CN=*.allbsd.org", Issuer "/C=US/O=GeoTrust+20Inc./CN=RapidSSL+20SHA256+20CA+20-+20G3"); Thu, 12 Jan 2017 00:51:25 +0900 (JST) (envelope-from hrs@FreeBSD.org) Received: from alph.allbsd.org (alph.allbsd.org [192.168.0.10]) by mail-d.allbsd.org (8.15.2/8.15.2) with ESMTPS id v0BFnnP1013784 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 12 Jan 2017 00:49:49 +0900 (JST) (envelope-from hrs@FreeBSD.org) Received: from localhost (localhost [IPv6:::1]) (authenticated bits=0) by alph.allbsd.org (8.15.2/8.15.2) with ESMTPA id v0BFnlIr013781; Thu, 12 Jan 2017 00:49:49 +0900 (JST) (envelope-from hrs@FreeBSD.org) Date: Thu, 12 Jan 2017 00:49:30 +0900 (JST) Message-Id: <20170112.004930.1372286639994163593.hrs@allbsd.org> To: citrin+bsd@citrin.ru Cc: freebsd-net@FreeBSD.org Subject: Re: fe80::1%lo0 From: Hiroki Sato In-Reply-To: <94a99b96-808b-8f50-a4a3-eec8659737cd@citrin.ru> References: <94a99b96-808b-8f50-a4a3-eec8659737cd@citrin.ru> X-PGPkey-fingerprint: BDB3 443F A5DD B3D0 A530 FFD7 4F2C D3D8 2793 CF2D X-Mailer: Mew version 6.7 on Emacs 25.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Multipart/Signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="--Security_Multipart(Thu_Jan_12_00_49_30_2017_204)--" Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.99 at gatekeeper.allbsd.org X-Virus-Status: Clean X-Greylist: Sender DNS name whitelisted, not delayed by milter-greylist-4.4.3 (mail.allbsd.org [133.31.130.32]); Thu, 12 Jan 2017 00:51:26 +0900 (JST) X-Spam-Status: No, score=-99.9 required=13.0 tests=CONTENT_TYPE_PRESENT, QENCPTR1,USER_IN_WHITELIST autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on gatekeeper.allbsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Jan 2017 15:51:39 -0000 ----Security_Multipart(Thu_Jan_12_00_49_30_2017_204)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Anton Yuzhaninov wrote in <94a99b96-808b-8f50-a4a3-eec8659737cd@citrin.ru>: ci> Hello, ci> ci> Why FreeBSD adds fe80::1%lo0 to the loopback interface? ci> ci> I know, that in IPv6 each interface should have a link-local address, ci> but ::1 can be considered as link-local: ci> https://tools.ietf.org/html/rfc4291#section-2.5.3 FreeBSD's IPv6 stack was written before RFC 4291 clarifies whether ::1 is a link-local address or not---currently the implementation does not recognize ::1 as an address with link-local scope. ci> I think fe80::1 is unnecessary can be removed. For all practical ci> purposes ::1 should be enough. No. It may work with no link-local address but an unexpected behavior can happen in the kernel even if it is not harmful actually. If we really want to remove it, address scope of ::1 needs to be changed throughout the kernel in a consistent manner first. -- Hiroki ----Security_Multipart(Thu_Jan_12_00_49_30_2017_204)-- Content-Type: application/pgp-signature Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEABECAAYFAlh2VAoACgkQTyzT2CeTzy0vTwCfSYMvmIenswh4+qf8DcI2qPu7 hD8AnjX6EZpQta8Vk4GGu1bvQ8rzetvt =dink -----END PGP SIGNATURE----- ----Security_Multipart(Thu_Jan_12_00_49_30_2017_204)----