IPv6: A Primer
With the Y2K panic fading into distant memory after a decade, the latest hot topic around the tech
virtual water cooler (AKA Twitter) is IPv6. So in the interest of informing and allaying concerns, ZyXEL
offers this brief text on the topic.
It’s a protocol – a rule that determines the format and transmission of data from one computer to
another over the Internet (Internet Protocol version 6) – that succeeds the 30 year‐old IPv4 which
provided 4.3 billion addresses. When it was written, no one could foresee a need for more.
In an intervie
w with the Sunday Morning Herald, Vint Cerf said, “I thought it was an experiment and I
thought that 4.3 billion IP addresses would be enough to do an experiment.” He also said that he didn’t
know that the experiment he started in 1977 would ever end. When asked about why he thought about
stopping at 4.3 billion addresses, he added “Who the hell knew how much address space we needed?”
Thanks to the popularity of the Internet and the adoption of so many computers, smart phones,
security cameras, TVs, and other Internet‐connected devices that each use an IP address to
communicate, the last of the IPv4 addresses were distributed in February 2011. IPv6 will provide many
more Internet addresses.
But IPv6 isn't compati
ble with older IPv4 hardware. The technology behind the Internet needs to be
upgraded. Although most Internet firms haven’t yet made the effort to become IPv6 compliant, a
growing number are putting in the time and money into making the transition.
IPv6 shifts to a 128‐bit IP address space, supporting a virtually unlimited number of devices;
approximately 340 undecillion (that’s 340 times 10 to the power of 36) possible addresses. Even with
the explosion of Internet usage and demand for new addresses, that should provide enough for many
What about good old IPv4? It’ll still be around, making the overlap process a little stickier. We believe
the transition will be gradual with most operator networks running both IPv4 and IPv6 protocol.
eliminate NAT and Port Forwarding features: all devices will be accessible on the public
network, making it easier for people to manage home automation, file sharing, online gaming, peer‐to‐
peer programs and other applications without requiring complex settings on their router. Firewall
technology can still be used to protect devices from unwanted access.
How to handle both IPv4 and IPv6 protocols so you don’t shut out any of
As ZyXEL’s IPv6 software demonstrates, there are three ways to implement IPv6 and
still handle IPv4:
This method implements both IPv4 and IPv6 on all
network points from the CPE to the edge
router. This allows for both IPv4 and IPv6 traffic to pass over the network, without using tunnels
or complicated NAT configurations.
Dual Stack Lite
“Lite” implements both IPv4 and IPv6 on the LAN side of the CPE, and utilizes an IPv6
tunnel through much of the core network to a network‐side IPv4/IPv6 NAT server. This allows for
both IPv4 and IPv6 traffic to pass over the network with only IPv6 addresses assigned to new end‐
user connections.IPv6 Rapid Deployment
IPv6 Rapid Deployment, or “IPv6 RD” for short, implements both IPv4 and IPv6 on the CPE and
utilizes an IPv6 tunnel through much of the core network to a network‐side IPv6 relay server.
This allows for both IPv4 and IPv6
traffic to pass over the network
although it does require both IPv4
and IPv6 address assignments to
new end‐user connections.
Mobile IPv6 is a standard that has added the roaming capabilities of mobile nodes in IPv6 networks. The
major benefit is that the mobile nodes (as IPv6 nodes) change their point‐of‐attachment to the IPv6
Internet without changing their IP address. This allows mobile devices such as smart phones to
automatically switch from one ne
twork to another without losing its connections. Mobile IPv6 can also
work with stationary/devices. It will probably be used in IP over WLAN, WiMax or BWA (Broadband
Mobile IPv6 will be highly valuable for real time peer‐to‐peer services and VoIP as they require always‐
Several security features like encryption are native to the new protocol. However IPv6 may offer more
opportunities for security breaches. While operating a dual stack offers an easier migration path, it
offers both the vulnerabilities of both protocols at once. While IPv6 carries more information in headers,
a larger address does not make them impervious to flooding.
IPv6 does offer a new feature called mobility. This uses both the real and the mobile address. The real
address is found in the extension header. But the mobile address is temporary and located in the IP
header. The temporary mobile address is more vulnerable to spoofing attacks on the home agent.
RIPE Labs, the security arm of Europe’s Regional Internet Registry, found in March 2011 that 3.5% e‐mail
received over IPv6 networks was spam. That’s not a lot – but it indicates that spammers have already
found a way to override IPv6 security
dministrators can expect to be quite busy adjusting to the new complexity and potential
exposure IPv6 brings. Going Forward IPv6 is a vital step in the growth of the Internet, offering great
advantages as well as challenges. As a leader in developing IPv6‐ready products, ZyXEL can help you
make the transition quickly and with a minimum of effort with no breaks in service. Talk to your ZyXEL