In standalone-ha.xml and standalone-full-ha.xml a modcluster socket-binding is defined. It has multicast-address parameter which has hard-coded value 224.0.1.105. I need to change this value when I use IPv6 addresses and I can't do it without modifying configuration xml. Although the modcluster is not related to messaging, when the multicast address is IPv4, servers don't create cluster on IPv6 addresses.