VIPABACKUP must specify an interface name and IPv6 address. The interface name and IPv6 address pair must match any preexisting dynamic VIPA definitions for either that interface name or IPv6 address. If using VIPABACKUP for an initial DVIPA activation, neither the interface name nor the IPv6 address can preexist. Furthermore, for the takeover and backup functions to succeed, if a corresponding VIPADEFINE is to be subsequently activated, the interface name and IPv6 address on the VIPADEFINE statement must match the VIPABACKUP statement.