Currently Hawkular-Services and agent run with -Djava.net.preferIPv4Stack=true to force IPv4 networking. WildFly and EAP have support for IPv6 and can run without that flag. There are users out there that only use IPv6 inside their (internal) networks. A quick smoke test shows that this does not work yet with Hawkular-Services Also Cassandra must be modified to accept IPv6 connections. See http://docs.datastax.com/en/cassandra/3.0/cassandra/configuration/configCassandra_yaml.html#configCassandra_yaml__listen_interface_prefer_ipv6