Let me add a bit more context here that would help.
One of the requirements for GlassFish v2/v2ur1 clustering and high availability area is that the cluster of instances and DAS have to be on the same subnet. This is a requirement for the In-memory replication and Shoal clustering modules. In these releases, we were not able to successfully employ and test the cross subnet features of Jxta.
Cross subnet support is coming up in the next release v2.1
The way to work around this limitation in v2 and v2 ur1 releases is to have the network router allow, between the subnets, multicast traffic for the cluster's heartbeat-address and heartbeat-port
There is still the issue of firewall between DAS and cluster nodes which I am not sure is supported or even the case of vmware based nodes.
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