Internet Protocol version 6 (IPv6)
is the updated and revised implementation of the current networking
protocol used around the world, IPv4. IPv6 was developed to solve many
of the limitations and challenges faced with the IPv4 protocol,
initially because of the fast growth of the Internet in the late 1980s
and early 1990s and the worry that available addresses would run out.
Twenty-plus years ago, the advances in computer networking allowed for
huge opportunities for sharing and accessing data between networks, and
the Internet Protocol, IPv4, was developed and implemented by the
largest Internet service providers (ISPs) that hosted the backbone of
the Internet. Organizations, including government institutions,
commercial businesses, and schools, started to move their internal
networks to this protocol. Although many organizations continued to
leverage other networking protocols, if you wanted to share and access
data across the Internet, you had to use IPv4. With this big push,
operating system development, network-ready applications, and
networking devices all included IPv4.
Network administrators had to work hard in
some cases to support the quick growth and to troubleshoot issues
because IPv4 required manual configuration of addressing on devices and
in most cases they also had to deploy and support a method of dynamic
addressing provided by, you guessed it, DHCP services. Neither the
manual nor automated addressing methods could keep track of all
addresses, and administrators had to tightly control and monitor
address usage, hence the need for IPAM.
The quick adoption and growth of Internet
networking by both private users and businesses began to quickly absorb
the usable IP address ranges, and some began to worry that there was a
serious risk of running out of IP addresses. When this occurred,
private IP ranges were defined, for use on internal networks only, and
Network Address Translation (NAT) was developed and leveraged to allow
devices on private IP ranges to access the Internet using a shared
Internet address. The organizations that used NAT found many uses for
this service, mainly managed on routers and firewalls/proxy servers,
but in some cases, with certain applications, NAT cannot function at
100%.
Separately, but simultaneously, as
organizations moved toward sharing data across the Internet with
business partners and between office locations, transmitting data
securely over the Internet became a requirement, because supporting
private point-to-point lines could not compare on price. Encrypted
tunnels, or virtual private networks, were created across the Internet,
and this is still in heavy usage today. The use of NAT and VPNs in some
earlier implementations proved to be challenging to configure because
IPv4 did not have clearly defined or inclusive security standards.
Because of this, different hardware and software vendors implemented
sometimes similar, but not always compatible versions of IP Security
(IPsec). So, for organizations to securely share or securely connect
their networks over the Internet, many times they had to use the same
vendors for software/hardware or resort to paying for higher-priced
private point-to-point connections. As time has passed, IPsec for IPv4
has advanced, and most implementations are compatible, but this IPsec
security also comes with more data overhead and utilizes more bandwidth.
Last but certainly not
least, with the daily expanding market of Internet services,
transferring of data, and the growing number of users on the Internet,
network utilization and IP address assignment are always increasing.
Streaming music and peer networking were some of the first types of
Internet applications to consume large amounts of bandwidth. Now
network utilization and bandwidth requirements are being driven higher
and higher by streaming video, social networking, Voice over IP (VoIP)
phones, email, Internet browsing and shopping, and the ever-growing
number of Internet-capable mobile devices (smartphones, tablets, and
even gaming consoles). Many organizations, including Internet and
telephone service providers, need a way to prioritize their traffic to
ensure that the most business-critical or mission-critical applications
have all the bandwidth they require and that the less-important
applications, such as those for streaming music, can suffer when
mission-critical applications require more throughput. To support this,
IPv4 quality of service (QoS) features were implemented on many
networks. However, because QoS was not a strict requirement for
software and hardware developers to support, many applications do not
include enough information in their data packets to sufficiently
distinguish their data so that QoS could effectively categorize and
prioritize the traffic (thus presenting a challenge to IPv4). For
example, QoS in many cases uses the port number, like HTTP 80, to
identify web browsing traffic. For an application to work through a web
proxy server, the application had to run on port 80 (a music or video
streaming application, for example). Therefore, categorizing video as
web traffic was incorrect, and the video could get the undesired tier
of priority, and this could be a good or bad thing depending on the
situation. Although deeper examination into an IPv4 packet allows IPv4
QoS to better prioritize traffic, that can also slow down traffic
handling, and when IPsec is used and IPv4 packets are encrypted, QoS
cannot do its job properly.
Ah, finally, IPv6 is here! IPv6 has been a
work in progress since the early1990s when it was first named IP Next
Generation. Originally, IPv6 was developed to solve the issue of
running out of addresses, but now it has grown to also include many
features that IPv4 was lacking or needed improvement/guidelines and
standardization. Some of the most prominent improvements IPv6 has over
IPv4 are as follows:
• IP addressing—IPv6
addresses are 128-bit addresses, IPv4 addresses are 32-bit. Although
this might seem only four times larger, the actual number of usable
addresses as compared is IPv4 232 addresses versus IPv6 2128 addresses.
• Automated addressing—IPv4
required manual IP addressing or a DHCP server to provide addressing
for newly connected network devices. IPv6 includes both stateful (same
as IPv4) and stateless addressing. Stateless addressing can be
described as each IPv6 adapter assigns itself a unique address based on
discoveries with other neighboring IPv6 stateless devices to enable
real automated networking and communication. This self-assigned
stateless address is also referred to as the link-local address.
• Included security—IPv6
includes detailed specifications for IPsec built in to the protocol.
This allows each software and hardware vendor to adopt these standards
to make securing communication and traffic between different
applications and devices simpler and more reliable. Also, the way IPsec
has been implemented in IPv6, encrypted data can still be categorized
and prioritized properly with QoS, without compromising the security of
the data.
• Included QoS—The
IPv6 header of each packet of data includes two main fields that allow
for QoS to perform better than IPv4. These fields, the Traffic Class
and Flow Label fields, can be used by software and hardware developers
to properly identify their data so that it can be prioritized and
routed correctly. The Traffic Class field is used much like the IPv4
header Type of Service (ToS) field, but the Flow Label field is key to
quickly identifying a flow or stream of packets, encrypted or not, to
allow the entire dataset to be transmitted without examining each
packet individually after the first packet is identified.
This list identifies just a few of
the key improvements of IPv6 over IPv4; there are many more. However,
if you are still not convinced that you need to learn IPv6, open a
PowerShell console session on a Windows Server 2012 Active Directory
domain controller and type Netstat -n and press
Enter. This will show you that without a doubt, IPv6 is in use, whether
you want to accept it or not. Just look for the IPv6 link-local
address, which will start with fe80:: (the link-local prefix).
