NAT 46 and
NAT 64
·
NAT 46 technology is used when you want to
connect an IPv4 to IPv6.
·
NAT 64 technology is used when you want to
connect an IPv6 to IPv4.
How we can make
communication between IPv4 and IPv6 possible?
- ·
Since IPv6 is not backward compatible with IPv4,
we’re left with the necessity of transition mechanisms, which fall into one of
three classes: - ·
Dual-stacked interfaces: The simplest solution
to IPv4 and IPv6 co-existence (not interoperability) is to make interfaces
“bilingual,” so they can speak IPv4 to IPv4 devices and IPv6 to IPv6 devices.
Which version they use depends either on the version of packets they receive from
a device or the type of address DNS gives them when they query for a device
address. Dual stack was the intended means of transitioning from IPv4 to IPv6,
but the assumption was that the transition would be complete before IPv4 was
depleted. That has not happened, so dual stacking becomes more complex: How do
you give every interface both an IPv4 address and an IPv6 address when not
enough IPv4 addresses are available to go around?
- ·
Tunnels: Tunnels are also about co-existence,
not interoperability. They allow devices or sites of one version to communicate
across a network segment—including the Internet—of the other version. So two
IPv4 devices or sites can exchange IPv4 packets across an IPv6 network, or two
IPv6 devices or sites can exchange IPv6 packets across an IPv4 network.
- ·
Translators: Translators create interoperability
between an IPv4 device and an IPv6 device by changing the header of a packet of
one version to the header of the other version.
- ·
Like other transition methods, translation is
not a long-term strategy and the ultimate goal should be native IPv6.
However translation offers two major advantages over tunneling:
- ·
Translation provides a means for gradual and
seamless migration to IPv6. - ·
Content providers can provide services
transparently to IPv6 Internet users.
