From owner-freebsd-net Mon Sep 24 21:48:45 2001 Delivered-To: freebsd-net@freebsd.org Received: from shuttle.wide.toshiba.co.jp (shuttle.wide.toshiba.co.jp [202.249.10.124]) by hub.freebsd.org (Postfix) with ESMTP id B39D537B413 for ; Mon, 24 Sep 2001 21:48:39 -0700 (PDT) Received: from localhost ([3ffe:501:4819:2000:200:39ff:fe97:3f1e]) by shuttle.wide.toshiba.co.jp (8.9.1+3.1W/8.9.1) with ESMTP id NAA00823; Tue, 25 Sep 2001 13:49:41 +0900 (JST) Date: Tue, 25 Sep 2001 13:48:21 +0900 Message-ID: From: JINMEI Tatuya / =?ISO-2022-JP?B?GyRCP0BMQEMjOkgbKEI=?= To: Joe Abley Cc: freebsd-net@FreeBSD.ORG Subject: Re: ipv6/gif/cisco syslog noise In-Reply-To: <20010921111029.H4205@buffoon.automagic.org> References: <20010919153739.K85635@buffoon.automagic.org> <20010920.050441.28824742.ume@mahoroba.org> <20010919164416.Q85635@buffoon.automagic.org> <20010921111029.H4205@buffoon.automagic.org> User-Agent: Wanderlust/2.6.0 (Twist And Shout-pre) Emacs/21.0 Mule/5.0 (SAKAKI) Organization: Research & Development Center, Toshiba Corp., Kawasaki, Japan. MIME-Version: 1.0 (generated by SEMI 1.13.7 - "Awazu") Content-Type: text/plain; charset=US-ASCII X-Dispatcher: imput version 980905(IM100) Lines: 43 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Hi, Thanks for the quick response. >>>>> On Fri, 21 Sep 2001 11:10:30 -0400, >>>>> Joe Abley said: > In this case, on the cisco router which terminates the tunnel, defining > the tunnel interface with a 126-bit netmask causes a /126 prefix to be > distributed in the IGP, and this provides reachability information for > both ends of the tunnel to other routers in the network. > If the cisco interface had been numbered with a 128-bit netmask, a > /128 prefix would have been distributed which would have provided > reachability information for the cisco tunnel interface, but not the > FreeBSD gif interface. Hence traffic sourced from the FreeBSD box using > that gif interface address as a source address would not get replies > routed correctly. Hmm, then, you might want to try the following configuration: ifconfig gif0 inet6 2001:438:1fff:ffff:8::32 prefixlen 126 that is, using a prefix length smaller than 128 *without* specifying the destination address. I'm not sure if this works well for FreeBSD 4.3, but it surely does at least for FreeBSD 4.4. Actually, The KAME/BSD kernel does not treat p2p interfaces differently from (NB)MA interfaces in terms of IPv6 addressing. In other words, it should be compatible with commercial routers such as Cisco and Juniper. > The reason for allocating four addresses (a 126-bit prefix) to the > point-to-point link stems from similar practice in IPv4, I think (it > wasn't my decision; it's current policy in AS6461). I'd use /64 instead of /126, since there is no reason to save address space in IPv6, but it is of course up to the site's decision. JINMEI, Tatuya Communication Platform Lab. Corporate R&D Center, Toshiba Corp. jinmei@isl.rdc.toshiba.co.jp To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message