If the router does not talk multicast or have igmp snooping enabled then any multicast traffic received is commonly treated as broadcast as a fail open strategy. It possibly depends on the switch though, all that I have encountered if incorrectly configured blat multicast over the entire network.
It is possible to configure totem(the corosync protocol) to use unicast udp traffic instead of multicast as multicast can be hard to get right in many environments (large enterprise with many different vendor switch equipment of varying ages over say a lab running off a single managed switch). HTH Gordon > -----Original Message----- > From: Alan Conway [mailto:[email protected]] > Sent: 21 November 2011 07:06 > To: [email protected] > Cc: Ilya Haykinson > Subject: Re: Corosync crashes after a few minutes > > On 11/12/2011 02:31 AM, Ilya Haykinson wrote: > > Managed to solve the problem by getting multicast enabled on the > router. > > > > What tripped me up was that the brokers would connect (making it seem > like > > multicast was working), only to lose connection. I would have > imagined that > > with multicast disabled on the router there wouldn't be any way for > brokers > > to discover each other. Do they fall back to using broadcast then? > > No, clustered brokers need multicast to talk to each other. There is a > TCP > connection to new brokers joining to give them an initial 'snapshot' of > the > state, but even that needs multicast to find out the IP address to > connect to. > > --------------------------------------------------------------------- > Apache Qpid - AMQP Messaging Implementation > Project: http://qpid.apache.org > Use/Interact: mailto:[email protected] Sophos Limited, The Pentagon, Abingdon Science Park, Abingdon, OX14 3YP, United Kingdom. Company Reg No 2096520. VAT Reg No GB 991 2418 08. --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:[email protected]
