Internet addresses are 32-bit quantities (AF_INET) or 128-bit quantities (AF_INET6) that represent a network interface. Every Internet address within an administered AF_INET domain must be unique. Every Internet address within a scope for AF_INET6 domain must be unique. An internet host can also have multiple Internet addresses. In fact, a host has at least as many Internet addresses as it has network interfaces. For IPv4 interfaces, there must be one unique address per interface. However, the same is not true for IPv6 interfaces. See z/OS Communications Server: IPv6 Network and Application Design Guide for more information.