Technical data

ServerIron ADX NAT64 Configuration Guide 1
53-1002288-02
DRAFT: BROCADE CONFIDENTIAL
Chapter
1
NAT 64 Overview
When the Internet Assigned Numbers Authority (IANA) standardized IPv4 in 1981, no one could
have foreseen that its seemingly plentiful pool of 4 billion addresses would become depleted. But
according to Internet World Stats, Internet usage grew by 444.8 percent between 2000 and 2010.1
With the increasing deployment of Internet-enabled mobile devices, smart-grid devices, and
cloud-based applications, the spike in usage is only going to increase in this decade.
Indeed, on February 3, 2011, the IANA allocated its last block of IPv4 addresses to five Regional
Internet Registries (RIRs) around the world. These registries assign IP addresses to Internet Service
Providers (ISPs), which in turn issue IP addresses for home and office machines, smart phones,
and other Internet-enabled devices.
Taking the place of the old protocol, IPv6 is designed not only to solve IPv4’s address scaling
challenge but also to rectify other shortcomings. Because of these new capabilities, however, the
designers of IPv6 were not able to make it backward-compatible with IPv4. This means devices
speaking different versions of Internet Protocol can no longer communicate with each other
natively, and applications that rely on such communication will fail.
The industry faces a challenging transition while it moves carefully from its current IPv4-capable
routers, switches, servers, and applications to IPv6-ready devices. Service providers—whether they
are providing content, hosting services, or Internet access—cannot add or accommodate new
customers unless their content is equally accessible to both IPv4 and IPv6 users.
Similarly, e-commerce sites need to accommodate customers without knowing which protocol
those customers’ client devices use. At the same time, multiple federal governments around the
world have enacted regulations forcing their agencies to adopt IPv6. As a result, service providers,
hosting services, and other content providers need to provide transition approaches during the
evolution period. Today there are several technologies that create a bridge between IPv4 and IPv6;
they use such techniques as translation, coexistence, tunneling, overlay, and more. The Network
(and Port) Address Translation between IPv6 to IPv4 model—generally known as NAT64—is a
mechanism for both the transition to IPv6 and the coexistence of IPv4 with IPv6.
NAT64 works with DNS64, essentially a DNS translation service, to enable client-server
communication between an IPv6-only client and an IPv4-only server and vice versa. It allows for
peer-to-peer communication where communication can originate from an end-node running either
of the two protocols. NAT64 utilizes a preassigned IPv6 prefix to algorithmically translate IPv4
addresses of IPv4 servers. Similarly, it translates the IPv6 addresses of IPv6 servers to and from
IPv4 addresses by installing mappings. Overall, the NAT64 model offers a non-intrusive and
seamless transition path for organizations looking to explore IPv6.
To facilitate seamless communication with the new breed of IPv6-only customers in addition to IPv4
customers, the Brocade ServerIron ADX Series offers a simple and cost-effective transition path to
IPv6 using a standards-based NAT64 gateway.
Topology A: The NAT64 gateway capabilities of Brocade ServerIron ADX enables organizations to
bring new IPv6 customers onboard while utilizing their existing IPv4-based infrastructures.