Comment 2 for bug 1409548

By default, different charms use different ports on the default multicast address, so you should not get any conflicts; I've been considering switching to auto-generated addresses (which is supported by corosync based on cluster naming) but that's currently a wishlist item.

Best practice would dictate using different multicast addresses per clustered service avoiding propagation of multicast traffic to broadly; this is configurable via the charms.