From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Arendt Subject: Re: Date: Mon, 27 Sep 2010 13:54:36 -0700 Message-ID: <4CA1048C.8020508@rincon.com> References: <20100927200500.GB25879@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: David Stevens , Jason Gunthorpe , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "netdev-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" To: Christoph Lameter Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On 09/27/10 13:23, Christoph Lameter wrote: > On Mon, 27 Sep 2010, David Stevens wrote: > >> Because a querier can set the robustness value and >> query interval to anything you want. In the original report, >> he's not running a querier. The fact that it's a new group >> doesn't matter -- these are per-interface. > > The per interface settings are used to force an IGMP version overriding > any information by the queriers. You would not want to enable that because > it disables support for other IGMP versions. Without the override > different version of IGMP can be handled per MC group. > If a network vlan has IGMPv3 capability, then it should be able to support both v2 and v3 Joins (clients). But if the vlan is IGMPv2 only, then an initial Join from a Linux client might go out as v3 (if it hasn't seen a query yet) and be ignored. I believe this is the case that force_igmp_version really addresses. And it turns out that force_igmp_version=2 doesn't fully work. If the host sees a IGMPv3 query, it still responds with a v3 Join despite the flag. Bug report and candidate patch here: https://bugzilla.kernel.org/show_bug.cgi?id=18212 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html