How Can I Configure AMQ and JGroups to use IPv6 addressing with Host Names?

Issue

I am trying to configure AMQ clustering using jgroups and GOSSIP. My jgroups configuration is similar to the following:

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="urn:org:jgroups"
        xsi:schemaLocation="urn:org:jgroups http://www.jgroups.org/schema/jgroups.xsd">

    <TCP />
    <TCPGOSSIP initial_hosts="router.example.com[52222]"/>
    <MERGE3/>
    <FD_ALL/>
    <VERIFY_SUSPECT/>
    <pbcast.NAKACK2 use_mcast_xmit="false"/>
    <UNICAST3/>
    <pbcast.STABLE/>
    <pbcast.GMS/>
<!--    <UFC/>-->
<!--    <MFC/> -->
    <FRAG2/>
    <pbcast.STATE_TRANSFER/>
</config>

I have verified that my DNS server returns both IPv4 and IPv6 addresses, but it appears that AMQ isn't using the IPv6 address. How can I force the broker to use IPv6 addressing?