What is The Difference Between IPv6 and IPv4?
Last Updated: 06-03-2013 , Posted: 01-27-2011
Confused by phrases like Internet Protocol (IP), IPv6, IPv4 and IPng? Webopedia explains the difference between IPv4 and IPv6, and looks at the topic of migrating to a 128-bit address space.
What is Internet Protocol -- IP?
IP (short for Internet Protocol) specifies the technical format of packets and the addressing scheme for computers to communicate over a network. Most networks combine IP with a higher-level protocol called Transmission Control Protocol (TCP), which establishes a virtual connection between a destination and a source.
IP by itself can be compared to something like the postal system. It allows you to address a package and drop it in the system, but there's no direct link between you and the recipient. TCP/IP, on the other hand, establishes a connection between two hosts so that they can send messages back and forth for a period of time.
There are currently two version of Internet Protocol (IP): IPv4 and a new version called IPv6. IPv6 is an evolutionary upgrade to the Internet Protocol. IPv6 will coexist with the older IPv4 for some time.
What is IPv4 -- Internet Protocol Version 4?
IPv4 (Internet Protocol Version 4) is the fourth revision of the Internet Protocol (IP) used to to identify devices on a network through an addressing system. The Internet Protocol is designed for use in interconnected systems of packet-switched computer communication networks (see RFC:791).
IPv4 is the most widely deployed Internet protocol used to connect devices to the Internet. IPv4 uses a 32-bit address scheme allowing for a total of 2^32 addresses (just over 4 billion addresses). With the growth of the Internet it is expected that the number of unused IPv4 addresses will eventually run out because every device -- including computers, smartphones and game consoles -- that connects to the Internet requires an address.
A new Internet addressing system Internet Protocol version 6 (IPv6) is being deployed to fulfill the need for more Internet addresses.
What is IPv6 -- Internet Protocol Version 6?
IPv6 (Internet Protocol Version 6) is also called IPng (Internet Protocol next generation) and it is the newest version of the Internet Protocol (IP) reviewed in the IETF standards committees to replace the current version of IPv4 (Internet Protocol Version 4).
IPv6 is the successor to Internet Protocol Version 4 (IPv4). It was designed as an evolutionary upgrade to the Internet Protocol and will, in fact, coexist with the older IPv4 for some time. IPv6 is designed to allow the Internet to grow steadily, both in terms of the number of hosts connected and the total amount of data traffic transmitted.
IPv6 is often referred to as the "next generation" Internet standard and has been under development now since the mid-1990s. IPv6 was born out of concern that the demand for IP addresses would exceed the available supply.
While increasing the pool of addresses is one of the most often-talked about benefit of IPv6, there are other important technological changes in IPv6 that will improve the IP protocol:
- No more NAT (Network Address Translation)
- No more private address collisions
- Better multicast routing
- Simpler header format
- Simplified, more efficient routing
- True quality of service (QoS), also called "flow labeling"
- Built-in authentication and privacy support
- Flexible options and extensions
- Easier administration (say good-bye to DHCP)
Recommended Reading: IPv6: Preparing for the Migration
The Difference Between IPv6 and IPv4 IP Addresses
An IP address is binary numbers but can be stored as text for human readers. For example, a 32-bit numeric address (IPv4) is written in decimal as four numbers separated by periods. Each number can be zero to 255. For example, 18.104.22.168 could be an IP address.
IPv6 addresses are 128-bit IP address written in hexadecimal and separated by colons. An example IPv6 address could be written like this: 3ffe:1900:4545:3:200:f8ff:fe21:67cf (see "What does an IPv6 address look like?")
A Dictionary of IPv6 Related Terms
Webopedia's Network and Internet Protocols Category offers definitions to hundreds of technology terms and phrases related to network protocols. You can view all related sub-categories and term definitions here.
Related IPv6 Articles
IPv6: Preparing for the Migration
IPv6 is here. With the move to a 128-bit address space will come a fundamental shift in the way you think about your network. Are you ready to migrate? Still learning about the challenges? Check in here as we add to our collection of IPv6 resources.
Is the U.S. Ready For The IPv6 Challenge?
In the third volume of its report to the government about IPv6 transition, Juniper Networks outlined some of the key challenges and initiatives the government will have to undertake in order to meet the federally mandated IPv6 transition deadline of June 2008.
We're going to spend some time teaching you a number of incredibly wonderful things about IPv6, such as why network administrators need to get their duffs up and implement it, bullet points to persuade the bosses, and, of course, how to actually use it.
Did You Know...?
The American Registry for Internet Numbers (ARIN) manages IP address space allocations for the U.S., Canada and the Caribbean region. ARIN is one of five global Regional Internet Registry (RIR) organizations that in turn receive their IP allocations from the Internet Assigned Numbers Authority (IANA). [Source: EnterpriseNetworkingPlanet]