Certain systems might have the following configurations:
An IPMP group is configured with underlying IP interfaces
A /etc/hostname.interface file exists for one underlying IP interface.
The physical hardware that is associated with the /etc/hostname file is missing.
With the new IPMP implementation where data addresses belong to the IPMP interface, recovering the missing interface becomes automatic. During system boot, the boot script constructs a list of failed interfaces, including interfaces that are missing. Based on the /etc/hostname file of the IPMP interface as well as the hostname files of the underlying IP interfaces, the boot script can determine to which IPMP group an interface belongs. When the missing interface is subsequently dynamically reconfigured on the system, the script then automatically adds that interface to the appropriate IPMP group and the interface becomes immediately available for use.