This will require coordination with JGroups; may not be possible if the change is considered incompatible by them for whatever release goes into AS 6.0.0.

JGroups uses some system properties to overrule whatever is in the protocol stack config file. This predates the addition of system property substitution handling to the JGroups parser and is IMHO more confusing than using explicit system property substitution syntax in the config file.

For AS 6 I'd like to use system property namespacing to allow JGroups to have it's mechanism, but not use it for the default AS configs. This would involve:

1) Having the AS startup switches (-b and -u) no longer set system property values in the jgroups namespace (e.g. jgroups.bind_addr and jgroups.udp.mcast_addr). Only set properties in the jboss names space (e.g. jboss.bind.address, jboss.partition.udpGroup).
2) Having JGroups' internal code ignore properties in the jboss namespace. This is the part that requires JGroups agreement.
3) Add explicit bind_addr="${jboss.bind.address} configs to all the AS protocol stacks.
4) Document how using -Djgroups.bind_addr, -Djgroups.udp_mcast_addr and -Djgroups.mping.mcast_addr can let people have the JGroups override behavior if they want it.