Starting in v9.0, IPv6 support is now available. Users can specify IP addresses in IPv6 format for both WildFly and WebSphere application servers.
Enabling IPv6 in Wildfly
WildFly installations are configured to use IPv4 by default. To use IPv6, remove the JVM argument “-Djava.net.preferIPv4Stack=true” from the WILDFLY_JAVA_OPTIONS property in the appserver.properties file. A deploy is required for the change to take effect.
Enabling IPv6 in WebSphere
WebSphere Application Server supports IPv6, IPv4, and an IPv4/IPv6 combination called mixed mode. The type of TCP/IP stack is controlled by the “java.net.preferIPv4Stack” and “java.net.preferIPv6Addresses” JVM arguments. To create a WebSphere environment using IPv6 requires that “java.net.preferIPv6Addresses” is set to true for the deployment manager, node manager, and server.