Which of the following can be used by dual-stack service providers supporting IPv4/IPv6 customers with dual-stack hosts using public IPv6 addresses and private IPv4 addresses?
A . NAT64
B . 6RD
C . 6to4 tunnels
D . Carrier-grade NAT
Answer: D
Explanation:
Carrier Grade NAT is a large-scale NAT, capable of providing private-IPv4-to-public-IPv4 translation in theorder of millions of translations. Carrier Grade NAT can support several hundred thousand subscribers with thebandwidth throughput of at least 10Gb/s full-duplex. With IPv4 addresses reaching depletion, Carrier GradeNAT is vital in providing private IPv4 connectivity to the public IPv4 internet. In addition, Carrier Grade NAT isnot limited to IPv4 NAT; it can also translate between IPv4 and IPv6 addresses.