From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Smith Subject: Re: 2.6.32 and Multicast group membership Date: Sat, 5 Jun 2010 21:03:58 +0930 Message-ID: <20100605210358.06e703df@lk-netdev.nosense.org> References: <4C057DF4.3000305@exegy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Net Dev To: "Mr. Berkley Shands" Return-path: Received: from smtp2.adam.net.au ([202.136.110.251]:51675 "EHLO smtp2.adam.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751940Ab0FELdU (ORCPT ); Sat, 5 Jun 2010 07:33:20 -0400 In-Reply-To: <4C057DF4.3000305@exegy.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 01 Jun 2010 16:39:00 -0500 "Mr. Berkley Shands" wrote: > starting in 2.6.32, my multicast connections stop getting data after > 60-100 seconds. > The identical user code works fine under 2.6.22 through 2.6.31. > > The NIC (an intel 82586) has two ports on the same subnet > (eth0 at 172.16.21.55/24 and eth1 at 172.16.21.56/24) > > if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&req, > sizeof(req))) > { > perror("setsockopt IP_ADD_MEMBERSHIP failed"); > ::exit(-1); > } > > If I do ADD_MEMBERSHIP on just one of these interfaces, the sockets > still get data. > But if I join on both interfaces, one or both will stop getting packets > after 60-100 seconds. Sniffing with tcpdump shows the Cisco layer 3 switch > is not getting its responses back to keep the multicast group open. While it could be a kernel change, that sounds like it might also be related to IGMP snooping on the Cisco switch. Any changes made to that recently? > The HP layer 2 switch does not seem to care, it keeps the data flowing > regardless > of which physical port the join is executed on. > This is expected behaviour on a 'dumb' layer 2 switch i.e. one that doesn't perform IGMP snooping and therefore doesn't suppress multicasts towards end-nodes that aren't subscribed. That further suggests a change on the Cisco. FWIW, I'm having no trouble with IPv4 multicast under 2.6.33, plugged into Cisco switch, with IGMP snooping, but not multicast suppression, enabled. > Changing IP_MULTICAST_ALL has no effect :-( > Did I miss something? New code that I have to specify to keep the Cisco > happy? > > tia > > Berkley > > > -- > > // E. F. Berkley Shands, MSc// > > ** Exegy Inc.** > > 349 Marshall Road, Suite 100 > > St. Louis , MO 63119 > > Direct: (314) 218-3600 X450 > > Cell: (314) 303-2546 > > Office: (314) 218-3600 > > Fax: (314) 218-3601 > > > > The Usual Disclaimer follows... > > > > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html