This attribute represents the maximum number of simultaneous IPv6 IA_PDs (delegated prefixes) that are permitted for CPEs connected to the CM.When the MaxCpeIpv6Prefixes is set to zero (0), all IPv6 CPE traffic from the CM is dropped. The CMTS configures this attribute with whichever of the ('Subscriber Management CPE IPv6 List (TLV 67)' plus 'Subscriber Management CPE IPv6 Prefix List (TLV 61) ') or ('Subscriber Management Control Max CPE IPv6 Addresses (TLV 63)') signaled encodings is greater, or in the absence of all of those provisioning parameters, with the MaxIpv6PrefixesDef from the Base object. This limit applies to learned and DOCSIS-provisioned entries but not to entries added through some administrative process at the CMTS. Note that this attribute is only meaningful when the Active attribute of the CM is set to 'true'. IPv6 IA_PDs s are counted against the CpeCtrlMaxCpeIpv6Prefixes in order to limit the number of simultaneous IA_PDs permitted for the CMs CPEs.