What is the difference between IPv4 & IPv6?

IPv4 vs. IPv6

The Internet Protocol version 4, or IPv4, is the defined standard in the world today, but it is being replaced by the more advanced IPv6, to help solve the IP address exhaustion problem that is looming on the horizon. IPv4 uses 32 bits to define each address, which, in total, is roughly four billion addresses. This was a huge number during its inception, but with the internet boom, this address pool is expected to run-out in 2010 or 2011. IPv6 uses 128 bits for each address. To put this in perspective, if you take the number of known stars in the universe, and square that number, the result will only be slightly larger than the number of addresses in IPv6.

The problem of IP exhaustion forced people to come up with complex ways to conserve addresses. The complex algorithms can be taxing for routers that needto decipher each packet, and determine its destination. IPv4 is also impaired when working with mobile networks, where the device can move from one network to another. IPv6 solves these problems, as the huge number of addresses makes the complex algorithms unnecessary.

The difference between the two, that most people would likely notice, is the appearance of the IP address. IPv4 uses four 1 byte decimal numbers, separated by a dot (i.e., while IPv6 uses hexadecimal numbers that are separated by colons. Due to the incompatibility of IPv4 and IPv6, translations have been made to enable their interoperation, that leads to addresses that look like ::ffff:

Another key advantage of IPv6, is the ability to carry larger payloads than the fixed amount allowed in IPv4. This is an optional feature, and IPv6 networks can still remain compliant to IPv4’s payload size. Despite of the numerous advantages of IPv6, the incompatibility still blocks its adoption. Only a meager 1% of the world’s networks have converted to IPv6, while the remaining 99% still use IPv4. This will change once IPv4 addresses are totally exhausted, and communication companies are forced to use IPv6 addresses.


1. An IPv6 address consists of 128 bits, while an IPv4 address consists of only 32.

2. IPv6 has a lot more usable addresses compared to IPv4.

3. IPv6 makes the router’s task more simple compared to IPv4.

4. IPv6 is better suited to mobile networks than IPv4.

5. IPv6 addresses are represented in a hexadecimal, colon-separated notation, while IPv4 address use the dot-decimal notation.

6. IPv6 allows for bigger payloads than what is allowed in IPv4.

7. IPv6 is used by less than 1% of the networks, while IPv4 is still in use by the remaining 99%.

Ron Jagannathan has written 15 articles

Ron is a Caffeine dependent life-form from Planet Earth who wants to be a Jedi Knight of cloud computing. A man of mystery and power, whose power is exceeded only by his mystery. Quantum Physicist, TransHumanist, Systems Architect, Unix Administrator, Artificial Intelligence, Machine Learning and DIY Gadget enthusiast. Believes that the Universe has a high probability of being a simulation.
But he's real and hopefully some of his readers are too.
email: Ron.Jagannathan@gmail.com ph: 202 355 5205
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“In a Unix Universe, God is known by a four letter word called root. To err is human...to really foul requires you to be root.. err.. god.” ― Ron Jagannathan

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