[Linux-cluster] multicast howto

[Steven Dake]

On Wed, 2006-04-26 at 18:47 -0600, Wolfgang Pauli wrote:
> Thanks!
> 
> First, I had to figure out how multicast works. Still don't fully understand 
> it. I can ping 224.0.0.1 and I get responses from all hosts in the same 
> subnet. It tried to ping 225.0.0.8 but that does not really work. But I don't 
> know whether it has to.
> I have changed the cluster.conf to have only two nodes. Just to get the basic 
> understanding. I have node dream on subnet 210 and neo on 223. They still 
> form their own clusters. Should I just try different addresses, or do the 
> switches/routers have to be programmed for that?
> 
> regards,
> 
> wolfgang
> 

you dont say whether you have routers or switches between the two
machines

it probably wont work across routers
it should work across switches as long as they a) dont have IGMP
filtering enabled or b) their IGMP implementation is good which most are
not
> <?xml version="1.0" ?>
> <cluster config_version="2" name="alpha_cluster">
>         <fence_daemon post_fail_delay="0" post_join_delay="3"/>
>         <clusternodes>
>                 <clusternode name="dream" votes="1">
>                         <multicast addr="225.0.0.9" interface="eth0"/>
>                         <fence>
>                                 <method name="1">
>                                         <device name="human" 
> nodename="dream"/>
>                                 </method>
>                         </fence>
>                 </clusternode>
>                 <clusternode name="neo" votes="1">
>                         <multicast addr="225.0.0.9" interface="eth0"/>
>                         <fence>
>                                 <method name="1">
>                                         <device name="human" nodename="neo"/>
>                                 </method>
>                         </fence>
>                 </clusternode>
>         </clusternodes>
>         <cman expected_votes="1" two_node="1">
>                 <multicast addr="225.0.0.9"/>
>         </cman>
>         <fencedevices>
>                 <fencedevice agent="fence_manual" name="human"/>
>         </fencedevices>
>         <rm>
>                 <failoverdomains/>
>                 <resources/>
>         </rm>
> </cluster>