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An Introduction to IPv4 and IPv6

ipv4 and ipv6

The Internet Protocol specifies the technical format of packets and the addressing scheme for workstations to communicate over a data network. The Internet Protocol is designed for use in interconnected systems of packet-switched computer communication networks (see RFC:791).

IP usually works in combination with the Transmission Control Protocol (TCP), which establishes a virtual connection between a source and a destination or with UDP.  As an analogy, UDP can be thought of as sending a postcard via the postal system. It permits a user to address a packet and drop it in the system/network whereby the user does not have direct contact with the receiver of the message packet. TCP/IP, on the other hand, is more like a bidirectional phone call, where a connection is established the connection between the two hosts so that the two hosts can communicate between themselves for some time with each party acknowledging what the other party is sending.

Internet Protocol Versions

The two versions of Internet Protocol in use are Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6).  IPv6 was designed when it became apparent that the number of allocated IPv4 addresses would eventually run out.  Protocol developers IPv6 as a replacement IPv4 and added many more added security features beyond solely adding exponentially more addresses than IPv4.  IPv4 and IPv6 are not interoperable and IPv6 will not be immediately replicable by IPv6.  While many transition mechanisms exist, host based solution where end hosts are simultaneously configured with both IPv4 and IPv6 is the preferred configuration. This “dual stack solution” allows for a single change on each host and provider shortcomings in terms of transit can be addressed separately on upstream devices.

Internet Protocol Version 4

Internet Protocol Version 4 (IPv4) is the fourth revision of the Internet Protocol (IP) used to facilitate communication over a network through an addressing system. It is currently the most popular Internet protocol used to connect devices to the Internet.  IPv4 uses a 32-bit address scheme allowing for a total of 232 addresses (slightly over 4 billion addresses).  Each device connecting to the Internet requires an IP address. That means that each device including cell phones, office phones, game consoles and computers each need their own IP address in order to connect and communicate over the Internet. With the ever-growing number of devices that need to connect to the Internet, it is no surprise that the amount of available IPv4 addresses will soon be exhausted. Already, there are more devices connected than there are routable IPv4 addresses.  This is possible through a technology known as NAT (Network Address Translation) which allows multiple machines to appear as a single routable address.  This comes with the cost of the complexity involved in supporting devices beployed behind a NAT device. 

Internet Protocol Version 6

Internet Protocol Version 6 (IPv6) is the latest version of Internet Protocol. It has been under development since the early 1990s.  Other benefits of IPv6 include:

•          No need for NAT (Network Address Translation) because there are enough IPv6 addresses for each device to have it’s own address

•          Configuration can be automatic

•          Eliminates the challenge of private address collisions

•          Improved multicast routing

•          A simplified packet header, which allows for more efficient forwarding

•          Built-in authentication and privacy support through IPSec in the protocol.

•          Flexible options and extensions to the header format

Comparing IPv4 and IPv6 IP Addresses

Data is transferred over the Internet in the form of network packets. The formats of IPv4 and IPv6 packets are drastically different as the new IPv6 design minimizes the packet header processing by routers.  Because of the drastic design differences, IPv4 and IPv6 are not interoperable, but can co-exist on the same network “wire”. 

An IP address is binary number but can be rendered in human readable form (text). IPv4 uses a 32-bit numeric address written in decimal as four numbers separated by dots. Each number is between zero and 255. For example, is an IP address.  It is indistinguishable from the integer, 3,232,236,294 to the end hosts, but is a more human friendly format.

IPv6 addresses are 128-bit IP address and expresses numbers that are so much larger than IPv4 that it is written in hexadecimal instead of decimal and is separated by colons. The numbers between the colons represent numbers between 0 and 65535 (0 to ffff, hex).  An example of IPv6 address could be written in the form: 3ffe:1900:4545:3:200:f8ff:fe21:67cf.

By the simple fact that IPv4 addresses are almost completely exhausted around the world, we know for certain that the world will be forced to adopt IPv6 in the near future. Since IPv4 and IPv6 addresses are not interoperable, dual stack solutions will have to be implemented so that your host machines will be able to communicate with other IPv4 or IPv6 hosts. If you’re a business owner, it’s crucial that you implement IPv6 in the immediate future so that your business is accessible by customers or potential customers who are already using IPv6.  Contact us now to learn more about IPv6 enablement

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