From owner-freebsd-net@FreeBSD.ORG Tue Nov 4 23:10:53 2003 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BC61016A4CE for ; Tue, 4 Nov 2003 23:10:53 -0800 (PST) Received: from shuttle.wide.toshiba.co.jp (shuttle.wide.toshiba.co.jp [202.249.10.124]) by mx1.FreeBSD.org (Postfix) with ESMTP id B1D6643FF7 for ; Tue, 4 Nov 2003 23:10:52 -0800 (PST) (envelope-from jinmei@isl.rdc.toshiba.co.jp) Received: from ocean.jinmei.org (unknown [3ffe:501:100f:13ff::6]) by shuttle.wide.toshiba.co.jp (Postfix) with ESMTP id 3D5A91521E; Wed, 5 Nov 2003 16:10:48 +0900 (JST) Date: Wed, 05 Nov 2003 16:10:45 +0900 Message-ID: From: JINMEI Tatuya / =?ISO-2022-JP?B?GyRCP0BMQEMjOkgbKEI=?= To: Barry Bouwsma In-Reply-To: <200311021403.hA2E3OE48213@NOSPAM.spam.NOSPAM.spam.NOSPAM.dyndns.dk> References: <200311021403.hA2E3OE48213@NOSPAM.spam.NOSPAM.spam.NOSPAM.dyndns.dk> User-Agent: Wanderlust/2.10.1 (Watching The Wheels) Emacs/21.3 Mule/5.0 (SAKAKI) Organization: Research & Development Center, Toshiba Corp., Kawasaki, Japan. MIME-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII cc: FreeBSD Networking Nerds Subject: Re: IPv6 autoconf addresses with changing RAs... X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 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, 05 Nov 2003 07:10:53 -0000 X-List-Received-Date: Wed, 05 Nov 2003 07:10:53 -0000 >>>>> On Sun, 2 Nov 2003 15:03:24 +0100 (CET), >>>>> Barry Bouwsma said: > I have one IPv6 machine behind a second, which second machine for > historical reasons has an IPv6 prefix/address that occasionally changes. > After this happens, the first host-only machine receives an additional > autoconf IPv6 address, but it still retains the old (now obsolete) IPv6 > autoconf address it had learned from this same router. The machines are > running kernels RELENG_4 from late-September-ish. Userland varies horribly. > What I want to happen, is that when the new IPv6 address is autoconf'ed, > the old one should disappear from the interface. (I've been too impatient > to watch if it disappears after time, during which time I cannot reach > the router's new address or the default route, as the old prefix which > it had is no longer present thanks to my hacked scripts. If I manually > delete the original IPv6 address, it seems that things work.) Does the following behavior of rtadvd(8) help you? Similarly, when an interface direct route is deleted, rtadvd will start advertising the prefixes with zero valid and preferred lifetimes to help the receiving hosts switch to a new prefix when renumbering. Note, how- ever, that the zero valid lifetime cannot invalidate the autoconfigured addresses at a receiving host immediately. According to the specifica- tion, the host will retain the address for a certain period, which will typically be two hours. The zero lifetimes rather intend to make the address deprecated, indicating that a new non-deprecated address should be used as the source address of a new connection. This behavior will last for two hours. Then rtadvd will completely remove the prefix from the advertising list, and succeeding advertisements will not contain the prefix information. At least rtadvd contained in FreeBSD 4.8R seem to support this behavior. JINMEI, Tatuya Communication Platform Lab. Corporate R&D Center, Toshiba Corp. jinmei@isl.rdc.toshiba.co.jp