From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265843AbUFDP51 (ORCPT ); Fri, 4 Jun 2004 11:57:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265865AbUFDPzK (ORCPT ); Fri, 4 Jun 2004 11:55:10 -0400 Received: from paris.dvs1.informatik.tu-darmstadt.de ([130.83.166.129]:31681 "EHLO paris.dvs1.informatik.tu-darmstadt.de") by vger.kernel.org with ESMTP id S265852AbUFDPy3 (ORCPT ); Fri, 4 Jun 2004 11:54:29 -0400 Date: Fri, 4 Jun 2004 17:54:23 +0200 From: "Wesley W. Terpstra" To: linux-kernel@vger.kernel.org Subject: Broken? 2.6.6 + IP_ADD_SOURCE_MEMBERSHIP + SO_REUSEADDR Message-ID: <20040604155423.GA5656@muffin> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! I am using the new IGMPv3 support in the 2.6.* series for Single Source Multicast (SSM). However, the kernel appears to (incorrectly) drop packets in some situations. What I do is this: open a UDP port, set it SO_REUSEADDR, bind it to port 6767, and then use IP_ADD_SOURCE_MEMBERSHIP to listen to multicast group 232.65.43.21 and with a command-line controlled sender. If I launch the same program twice with different senders, the first program ceases to receive multicast packets. (Neither from its own sender, nor the second program's sender) The second program receives packets from its designated sender only (as expected). I know from tcpdump that the switch is delivering messages from the first designated sender. The kernel is simply not giving them to the application. Some more observations: If both programs specify the same sender, then both programs receive the message (as expected). This is not an issue with subscribing to multiple senders in general. A single program listening to two senders does receive messages from both. This seems like a bug to me. PS. I am not subscribed to this list, so please CC me. -- Wesley W. Terpstra