When deploying Coherence with Foundry switches please be aware of the following:
Foundry switches have shown to exhibit difficulty in handing multicast traffic. When deploying on with Foundry switches it is recommend that you utilize the Multicast Test to ensure that all machines which will be part of the Coherence cluster can communicate over multicast.
If you encounter issues with multicast you may consider changing your configuration to unicast-only via the Well Known Addresses feature.