Multicast doesn't seem to be working on RHEL 5.5

What's the output of netstat -gn?

By default, your multicast joins are going to go out of the lowest-numbered interface cough, eth0. Since you're attempting to do this via eth2, you're going to need another step to establish connectivity.

Does the test utility provide a means of specifying the interface? If so, you'll need to explicitly state "eth2". If that is not an option, you can add another static route to make sure your multicast traffic uses that interface.

Something like:

route add -net 224.0.0.0 netmask 240.0.0.0 dev eth2 (route all multicast through eth2)

Try that...

If it all works, be sure to make everything persistent by creating a /etc/sysconfig/network-scripts/route-eth2 file with your static routes.

Edit:

If you have the ability to select interfaces in your application, then you DO NOT need any static routes on your interfaces. It would be up to the Oracle test utility to handle IGMP.

Try that first...

If that does not work, please verify if multicast is enabled on the network switch that the systems are connected to. What type of switches are they? I can give more detail instructions based on the switch model/type. If Cisco, for instance...

sh ip igmp snooping
sh run | i multicast-routing

Following that, there seems to be a known bug related to this product. Are you certain that you're fully-patched? It appears to be an unpublished patch, so you may have to go to Oracle to resolve this if everything else is in place.

See: Grid infrastructure multicast issue - Oracle Bug 9974223