Clients may support both IPv4 and IPv6 simultaneously (dual-stack hosts.) In this case, one subscriber host entry is created for the IPv4 address family and one for the IPv6 instance. The scaling limits apply for all entries, regardless of address type.
For DHCP, these subscriber hosts are fully independent (as they are set up through different protocols), but for PPPoE hosts or RGs, the ESM information in both subscriber host entries is linked together through the PPPoE session.