IPv6 architecture provides for a plug-and-play environment by automatically generating IP addresses when they are not manually configured. To guarantee predictable IP address association with specific systems, you must disable this capability on z/OS® Communications Server stacks through manual configuration.
The stack automatically generates link-local IP addresses using the link-local prefix and the interface ID. To make these addresses predictable, you must manually configure the INTFID parameter on all IPv6 INTERFACE statements. If you are enabling dynamic XCF, you must also manually configure the DYNAMICXCF INTFID parameter on the IPCONFIG6 statement.
Some IPv6 interface types support router autogeneration. When this is enabled, the responsible router informs the stack about prefixes that are supported and the stack generates IP addresses from those prefixes and the interface ID. You must disable this capability on all interfaces that support it, by manually configuring at least one prefix or address using the IPADDR parameter on the INTERFACE statement.
These considerations for IPv6-enabled stacks do not apply to the IBM® zEnterprise® System (zEnterprise) intranode management network (INMN) that is accessed through OSA-Express for Unified Resource Manager (OSM) interfaces. Traffic over that network is protected by OSM access control rather than network access control.