[pve-devel] corosync, multicast problem because of vmbr multicast_snooping enabled

Alexandre DERUMIER aderumier at odiso.com
Sat Mar 9 09:56:19 CET 2013


>>I first need to debug corosync here next week - I still not understand whats happens. 

Ok, no problem. (I see that a new corosync 1.4.5 has be released)




Some more infos about igmp queries.

We can have only 1 igmp quierier on a vlan. If multiple quierier exist, an election mecanism exist, and the querier with lowest ip should win.

So it's possible that a proxmox host, is the igmp quierier for your whole network. (including physical switches).

I think it can be pretty bad, as if you have some host problem (network driver, bridge bug, iptable filter,...), it can break igmp response and 
may cause potentential igmp snooping break.
Also if you reboot the host which is the igmp quierier, a new election will occur.

So disable igmp query on linux bridge should be disable by default. 




----- Mail original ----- 

De: "Dietmar Maurer" <dietmar at proxmox.com> 
À: "Alexandre DERUMIER" <aderumier at odiso.com>, "Michael Rasmussen" <mir at datanom.net> 
Cc: pve-devel at pve.proxmox.com 
Envoyé: Samedi 9 Mars 2013 09:31:26 
Objet: RE: [pve-devel] corosync, multicast problem because of vmbr multicast_snooping enabled 

> @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 

I first need to debug corosync here next week - I still not understand whats happens. 


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