IPv4/IPv6 transition using DNS64/NAT64: Deployment issues

IPv4 address space is almost exhausted. Usage of IPv6 address by client end hosts is limited due to small percentage of domain names that have IPv6 address. This paper presents practical testing in ISP that gives its users IPv6 addresses and provides them transparent access to both IPv4 and IPv6 Internet locations. DNS64/NAT64 translation mechanism is used for this purpose. Tests measure resource requirements on ISP side and effects on client experience. Results show that additional DNS64 processing causes no visible impact on DNS server CPU load. There is requirement for NAT64 device at ISP on path between IPv6 users and IPv4 Internet. Test results show that memory requirements for this device are small and achievable with standard hardware devices used by ISPs. Measured increase in RTT from IPv6 clients to IPv4 Internet is less than 2%. Conclusion is that DNS64/NAT64 translation system is viable solution for ISP.