From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kristoff Bonne Subject: ipv6 multicasting: "interface-local" scope Date: Thu, 14 Apr 2011 19:23:07 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from lo.gmane.org ([80.91.229.12]:46578 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192Ab1DNRZH (ORCPT ); Thu, 14 Apr 2011 13:25:07 -0400 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1QAQHy-000488-8D for netdev@vger.kernel.org; Thu, 14 Apr 2011 19:25:06 +0200 Received: from 91.181.176.68 ([91.181.176.68]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 14 Apr 2011 19:25:06 +0200 Received: from kristoff.bonne by 91.181.176.68 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 14 Apr 2011 19:25:06 +0200 Sender: netdev-owner@vger.kernel.org List-ID: Hi, (This is a repost of a message I posted yesterday in linux.network.general but to which I have not seen any replies). If I understand RFC 4291 correctly, the ipv6 multicast ip-addresses ffx1: are "interface local" scope. In draft-ietf-ipngwg-scoping-arch-02, I read this: "The interface-local scope spans a single interface only; a multicast address of interface-local scope is useful only for loopback delivery of multicasts within a single node, for example, as a form of inter-process communication within a computer". This is exactly what I want to do for an application I am working on. However when I try it and make a small program that sends out UDP packats to the ipv6 multicast address ff11::1234, I do see them show up on remote machines on my LAN! So it looks like these packets do leave my local compute which -I think- is the opposite of what RFC4291 tells me should happen. Am I missing something? or is this a bug? The machine on which I have tested this runs ubuntu 10.04.1 LTE with kernel 2.6.32-30-generic Anybody any ideas? links: - RFC4291: http://tools.ietf.org/html/rfc4291#section-2.7 - draft-ietf-ipngwg-scoping-arch-02: http://tools.ietf.org/html/draft-ietf-ipngwg-scoping-arch-02) Cheerio! Kr. Bonne.