IPv4 vs. IPv6 Full Comparison

Key Points

• IPv4 was deployed in 1983 by ARPANET and is responsible for 94% of internet traffic.
• IPv4 is limited to four billion unique addresses.
• IPv6 has a highly unrealistic limitation of three hundred and forty trillion, trillion, trillion potential unique addresses.
• Average PC users will likely not see a difference in performance between IPv4 and IPv6.
• IPv6 was created to surpass the address limitations of IPv4.
• IPv4 and IPv6 cannot communicate with each other.
• IPv4 and IPv6 can be used together on the same network. This is called a dual-stack.
• IP addresses are stored as binary numbers. DNS, or Doman Name Service, is the reason web users can type in a website address like “www.bing.com” rather than a unique string of binary numbers.
• IPv4 has run out of addresses to assign.
• IPv6 and IPv4 coexist currently, but IPv6 is scheduled to be the future protocol for all addresses.

Internet Protocol, or IP, is a methodology that allows computers to send data to one another via the internet. This methodology, or protocol, is what allows data packets to be sent from one “host” computer to another computer via the most direct route possible.  

The first non-experimental IP, IPv4, was developed during the 1970s. Unfortunately, it wasn’t improved much in the interim, so IPv6 was created to handle IPv4’s shortcomings. The problem with IPv4 is that it can only handle four billion unique IP addresses, while there are far more devices than that on the internet. IPv6 addresses that issue by replacing IPv4’s 32-bit IP address with a 128-bit IP address, which will allow nearly three hundred and forty trillion, trillion, trillion addresses, enough for everybody on the planet to have a billion devices of their own.  

Read on to find out more about the differences between IPv4 and IPv6.

IPv4 vs IPv6: The Key Differences Explained

Internet Protocol is the main set of rules that governs the exchange or transmission of data between devices on separate networks. It does this through two main functions. First, it addresses the host computer via their “unique IP address.” (Every computer has one or more IP address.) This is nearly the same as having a physical address.

Without a designation for where data is sent, it’s impossible for your computer or the network to know where to send it. So, internet protocol gives every host connected to the internet an IP (internet protocol) address. The second function is routing.

Now that internet protocol has dictated the header profile of packets to send, the best possible pathway to send the packet has to be created. This is mostly done through the hardware component called the router.

For example, if a physical parcel needed to be shipped from Alaska to Spain, the delivery company would make decisions on which flight paths are best for the package to take in order for it to be delivered at the quickest speed rather than cycling through every destination until it hits the intended receiver. The idea is just as simple for internet protocol.

IPv4, the first non-experimental version of IP, is the cornerstone of the internet as we know it, but was originally developed in the 70s and has seen little improvement since. This has led to the creation of IPv6 to handle the ineptitude of IPv4. The big problems of IPv4 were created by the massive scale of the internet. IPv4 can only handle four billion unique addresses.

This may seem like a lot, but it’s nowhere near enough to address every device on earth. IPv6 replaces the IPv4 32-bit IP address with a 128-bit IP address. This allows nearly three hundred and forty trillion, trillion, trillion addresses. That’s enough for every person on earth to have about a billion devices on their own.

Another essential component to both IPv4 and IPv6 is the Domain Name Service (DNS). While internet protocol has assigned unique binary number values to every device connected to the internet, these numbers are far too wieldy for a human to remember or store.

The Domain Name Service was created to make a system where addresses can be associated with names. The result is that a web user can type in an address like “www.google.com” rather than a unique string of 32 numbers for each site they want to visit. DNS then translates the name into the unique IP address so that IPv4 or IPv6 can route the transmission.

New devices are likely to be utilizing the IPv6 address system as IPv4 ran out of addresses to give. This is not to say that individual devices within a network like the Xbox One gaming console can’t use either IPv4 or IPv6. As an example, devices within a network are given separate designations that work similarly to street addresses and apartment numbers. The address to the building may be the same, but sub addresses within the network keep everything organized for proper networking.

IPv4 vs. IPv6 Side-by-Side Comparison

What Is IPv4?

Internet Protocol version four, or IPv4, is a widely used internet protocol for identifying devices on a network using an address system. It was deployed by ARPANET for production in 1983. It uses a 32-bit address system that allows for four billion unique addresses. It has been widely considered the primary internet protocol and is responsible for 94% of internet traffic and security.

IPv4’s Limitations

Technological advancement across the world has proliferated the number of computing devices with internet connectivity well beyond the vast limitations of IPv4’s address system. Four billion individual addresses may seem like an extraordinary amount, but this number has long been surpassed by existing connected devices. As in the example used in the first section of this page, a routing system without an address isn’t very useful.

For this reason, IPv6 was created to deal with the unforeseen shortcomings of IPv4.

IPv4 Features

• Connection-less protocol
• Allows for virtual communication layer over diversified devices
• Requires less memory
• Heavily supported protocol

What Is IPv6?

Internet protocol version six, or IPv6, is the most recent internet protocol released. It replaces the 32-bit address system used in IPv4 with a 128-bit address system. This increases the total number of possible unique addresses from four billion to an even more seemingly unrealistic number, three hundred and forty trillion, trillion, trillion. Both IPv4 and IPv6 operate at the same speeds limited by hardware capability.

IPv6 Features

• Hierarchical addressing and routing infrastructure
• Stateful and Stateless configuration
• QoS support

Key Differences

• IPv4 uses 32-bit binary number IP addresses while IPv6 uses 128-bit binary number addresses.
• IPv4 uses a numeric addressing method. IPv6 uses an alphanumeric addressing system.
• IPv4 binary number bits are separated by a dot(.). IPv6 binary number bits are parsed with a colon.
• IPv4 allows for twelve header fields. IPv6 only allows for eight header fields.
• IPv4 supports broadcast. IPv6 does not support broadcast.
• IPv4 has checksum fields. IPv6 does not have checksum fields.
• IPv4 supports Variable Length Subnet Mask (VLSM). IPv6 does not support VLSM.
• IPv4 uses Address Resolution Protocol (ARP) for MAC address mapping. IPv6 uses Neighbor Discovery Protocol (NDP) for MAC address mapping.