>>Again I only presume. Given only a psychical nic I guess multicast is >>by default carried unless explicitly stated otherwise.
I'm reading the cisco and hp documentations, if igmp snooping is enabled, it require igmp queries to work. So switches need to send igmp queries (it's the default on cisco switch if multicast is enabled) (igmp snooping need igmp queries). But having igmp_snooping disable on a physical switch (or linux bridge), should forward all multicast by default to all ports. Igmp snooping in linux bridge has been added in kernel 2.6.34, and I think multicast worked before that on linux bridges ;) Now it seem that igmp queries coming from linux bridge can conflict with igmp queries from physicals switchs. That's why igmp queries are now disable in newer kernels https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c5c23260594c5701af66ef754916775ba6a46bbc "Sending general queries was implemented as an optimisation to speed up convergence on start-up. In order to prevent interference with multicast routers a zero source address has to be used. Unfortunately these packets appear to cause some multicast-aware switches to misbehave, e.g., by disrupting multicast packets to us. Since the multicast snooping feature still functions without sending our own queries, this patch will change the default to not send queries. For those that need queries in order to speed up convergence on start-up, a toggle is provided to restore the previous behaviour. " So maybe this igmp queries conflict is the source of the problem I had. But it seem difficult to disable it from linux bridge, if igmp snooping group could be created on physical switchs. @Dietmar Maybe the upgrade should be done like this: - disable igmp snooping on physical switches (if user use it) - upgrade kernel of each node and reboot them. (they should communicate with old and newer kernel) - re-enable igmp snooping on physical switch when all nodes are upgraded ----- Mail original ----- De: "Michael Rasmussen" <m...@datanom.net> À: pve-devel@pve.proxmox.com Envoyé: Vendredi 8 Mars 2013 19:45:33 Objet: Re: [pve-devel] corosync, multicast problem because of vmbr multicast_snooping enabled On Fri, 08 Mar 2013 19:34:56 +0100 (CET) Alexandre DERUMIER <aderum...@odiso.com> wrote: > > So, how can do you multicast with linux without bridge ? > Like simply use multicast from ip on eth0 ? > (Because it doesn't send igmp queries in this case) > Again I only presume. Given only a psychical nic I guess multicast is by default carried unless explicitly stated otherwise. -- Hilsen/Regards Michael Rasmussen Get my public GnuPG keys: michael <at> rasmussen <dot> cc http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xD3C9A00E mir <at> datanom <dot> net http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE501F51C mir <at> miras <dot> org http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE3E80917 -------------------------------------------------------------- Test input for validity and plausibility. - The Elements of Programming Style (Kernighan & Plaugher) _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
