From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Joakim Tjernlund" Subject: RE: Multicast problem Date: Tue, 16 Oct 2007 19:31:24 +0200 Message-ID: <002501c8101a$6005dc10$04ac10ac@Jocke> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "'Netdev'" To: "'David Stevens'" Return-path: Received: from mail.transmode.se ([83.241.175.147]:42018 "EHLO tmnt04.transmode.se" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751631AbXJPRb2 (ORCPT ); Tue, 16 Oct 2007 13:31:28 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org > -----Original Message----- > From: David Stevens [mailto:dlstevens@us.ibm.com] > Sent: den 16 oktober 2007 19:05 > To: joakim.tjernlund@transmode.se > Cc: Netdev > Subject: Re: Multicast problem > > If you have icmp_echo_ignore_broadcasts set to 1, it won't respond to > multicasts. That should be all you need to do for 224.0.0.1. > > Some smart switches rely on IGMP snooping to determine group > membership, > and some of those don't understand IGMPv3, so if you have no v1 or v2 > queriers > on the network, you can force the IGMP version to be 2 instead of the > default 3 > by using a sysctl. Tried forcing igmp from 3 to 2, didn't help > But that's not the issue for 224.0.0.1, since the > all-hosts group > is not reported via IGMP. > > You might check the contents of /proc/net/igmp and > /proc/net/dev_mcast to dev_mcast and igmp looks: root@Challenger:/proc/net# m dev_mcast 1 eth0 1 0 01005e000001 2 eth1 1 0 01005e000001 root@Challenger:/proc/net# m igmp Idx Device : Count Querier Group Users Timer Reporter 1 eth0 : 1 V3 E0000001 1 0:00000000 0 2 eth1 : 1 V2 E0000001 1 0:00000000 0 4 lo : 0 V3 E0000001 1 0:00000000 0 I can't tell if that's OK or not. > make > sure they have entries for the group. If so, I'd guess it might be a > driver or device issue. Could it be some missing kernel config? This is a custom board so I could very well miss something I kernel config or user space config. Thanks for your help, if you have any more ideas you are most welcome to share :) Jocke > > +-DLS