This attribute represents the prefix length associated with the IP prefix (IPv4 or IPv6) that is either set via provisioning or learned via address gleaning of the DHCP exchange or some other means. For IPv4 CPE addresses, this attribute generally reports the value 32 (32 bits) to indicate a unicast IPv4 address. For IPv6 CPE addresses, this attribute represents either a discrete IPv6 IA_NA unicast address (a value of 128 bits, equal to /128 prefix length) or a delegated prefix (IA_PD) and its associated length (such as 56 bits, equal to /56 prefix length).