Comment # 7 on bug 960118 from Bin Liu

from totemudp.c, I found the function to build socket connect,
/*
* If the interface is up, the sockets for totem are built.  If the interface is
down
* this function is requeued in the timer list to retry building the sockets
later.
*/
static void timer_function_netif_check_timeout.

And if you execute "brctl delif virbr0 vnet2", the network state is still up(
corosync gets link state by calling getifaddrs), so the vm kernel still think
network is still up. 

And I need to confirm how corosync selects an interface to run.