There are compatibility issues to consider when configuring the IP version for cells.
The product supports Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6). IPv6 support was introduced with IBM® i release V5R4, and although WebSphere® Application Server V6.0 only supports IPv4, when running on V5R4 and later releases of IBM i, WebSphere Application Server V6.1 and later support IPv4 and IPv6. When defining a node, you must specify the host name as a string or as a 32-bit numerical address.
When you create a new profile, you can optionally specify the host name for the profile by using the -hostName parameter. If you do not specify the host name, the host name for the profile defaults to the fully qualified host name for the server. If you choose to use the -hostName parameter and want to specify the IP address for your server, specify the valid 32-bit numerical address.
The product uses multicast broadcasting at the node
level to allow a node agent to discover the managed processes in the
node. IPv4 and IPv6 addresses are not compatible. Therefore, to allow
a WebSphere Application Server node to
run after initial installation, both IPv4 and IPv6 multicast addresses
are initially defined in the node agent configuration, and when a
node agent starts, both addresses are tried in sequence. Delete the
NODE_IPV6_MULTICAST_DISCOVERY_ADDRESS address after installation because,
by limiting the multicast discovery to the known protocol, the node
agent runs more efficiently.