Configuring a TCP/IP stack to generate IPv6 temporary addresses

To implement the mechanism defined in RFC 4941 regarding the use of randomly generated interface IDs, you must first configure a TCP/IP stack to generate IPv6 temporary addresses.

Before you begin

Before you configure a TCP/IP stack to use IPv6 temporary addresses:

Understand IPv6 stateless address autoconfiguration. See Stateless address autoconfiguration for a description of autoconfigured addresses, both public and temporary.
Determine whether you have a client application that would benefit from using temporary autoconfigured addresses. Temporary addresses are designed to be used with short-lived client connections.
Determine whether stateless address autoconfiguration is being used for one or more of the OSA-Express IPAQENET6 interfaces that are defined in the TCP/IP profile. Temporary autoconfigured addresses can be generated only for an OSA-Express IPAQENET6 interface that is using autoconfiguration (the IPADDR parameter is not specified with the IP address or prefix on the INTERFACE statement).

Procedure

Perform the following steps to configure a TCP/IP stack to generate IPv6 temporary addresses:

Enable the generation of temporary addresses by configuring the TEMPADDRS parameter on the IPCONFIG6 statement. For more information about the TEMPADDRS parameter, see the IPCONFIG6 statement in z/OS Communications Server: IP Configuration Reference.
(Optional) Set the preferred lifetime and the valid lifetime for temporary addresses by configuring the parameters PREFLIFETIME preflifetime VALIDLIFETIME validlifetime on the IPCONFIG6 statement. Default values are used if you do not configure these parameters. The preferred lifetime and valid lifetime values apply to all temporary addresses on the TCP/IP stack. For more information about preferred and valid lifetimes see Stateless address autoconfiguration. For more information about the PREFLIFETIME and VALIDLIFETIME parameters, see the information about the IPCONFIG6 statement in z/OS Communications Server: IP Configuration Reference.
(Optional) Limit the IPv6 prefixes for which temporary addresses can be generated by configuring the TEMPPREFIX parameter on one or more INTERFACE statements. In most cases, you can use the default value TEMPPREFIX ALL, which enables temporary addresses to be generated for all prefixes that are learned from router advertisements over the interface. If you need to limit the prefixes for which temporary addresses are generated for an interface, you can specify the TEMPPREFIX parameter on the INTERFACE statement. For more information about the TEMPPREFIX parameter, see the information about the IPAQENET6 INTERFACE statement in z/OS Communications Server: IP Configuration Reference.
Guideline: If SOURCEVIPA is enabled and the SOURCEVIPAINT parameter is configured for an interface, the default source address selection algorithm selects an address from the addresses for the source VIPA interface, not from the addresses for the outbound interface. Specify TEMPPREFIX NONE to disable unnecessary generation of temporary addresses for the outbound interface. For more information, see VIPA considerations with source address selection.

What to do next

When you are done, configure the client application to use temporary addresses. See Enabling a client application to use IPv6 temporary or public addresses.