From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 13 Jul 2001 15:06:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 13 Jul 2001 15:06:21 -0400 Received: from yap.isi.edu ([128.9.160.146]:12933 "EHLO yap.isi.edu") by vger.kernel.org with ESMTP id ; Fri, 13 Jul 2001 15:06:07 -0400 To: linux-kernel@vger.kernel.org Subject: multicasting: IP_MULTICAST_LOOP & ttl==0 bug? From: Yuri Date: 13 Jul 2001 12:06:08 -0700 Message-ID: User-Agent: Gnus/5.0803 (Gnus v5.8.3) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi. I seem to have found out that depending on whether or not multicast loopback is enabled outgoing multicast packets with ttl set to 0 are treated differently. In both cases I set ttl of outgoing packets to 0 (with IP_MULTICAST_TTL setsockopt). If multicast loop is enabled, packets remain local for the machine and are not sent onto the wire (expected behavior). However, if I disable multicast loopback, packets with ttl 0 show up on the wire. Is this a bug or I'm missing something? Kernel version is 2.4.3-12. Thanks, -Yuri P.S. Please CC.