What is the Difference Between IPv4 and IPv6?

  • July 24, 2024·
  • by Hazel Salinas·

IPv4 and IPV6: Connection is Key

In today’s blog, which is part of the IP Address mini-series of our expansive “What is” series, we go over a subject that is related to our previous blog: What is IPv4 and IPv6 and the difference between then?

IPv4

Let’s start with the basics: “IP” stands for Internet Protocol and “v4” stands for Version Four. Therefore, “IPv4”. Currently, IP addresses are based on version 4 of the internet protocol, where there are 4 sets of numbers ranging from 0-255. For example (127.198.30.245). IPv4 is the most widely used system for identifying devices on a network.

As we explained in a Knowledge Base article, a valid IPv4 address must be in the form of xxx.xxx.xxx.xxx, where xxx is a number from 0-255. There are a few reserved addresses (RFC 1918) that cannot be used. 10.x.x.x cannot be used along with 192.168.x.x, 172.16.0.0 to 172.31.255.255. If you are using a router, your machine will likely have one of these, and you should see this tip for more details. If you have an IPv4 address in this format, but do not have a router, your ISP may be using a NAT network, which will prevent you from running a server.

While the internet seems infinite, the number of possible IPv4 addresses is limited to 4,294,967,296.

IPv6

With IPv6, however, the number of possible IP addresses jumps to a staggering 340 undecillion (that’s 340 followed by 36 zeros)!

As we explained in a previous blog, IPv6 is an Internet addressing system that is designed to replace IPv4. It works in a very similar way as IPv4 but offers some additional benefits.  As the pool of available IPv4 addresses diminishes, there was a need to implement a protocol that offers a much larger pool of IP addresses to accommodate the ever-growing demand in the IP space.  We continue to see an increase in the number of Internet Service Providers (ISPs) that are providing IPv6 connectivity. This means that you may already be using IPv6 and don’t even know it.

Under the IPv6 protocol, domain names like noip.com are changed into IP addresses via DNS as usual, but instead of the IPv4 DNS record type A, IPv6 uses record type AAAA, often referred to as “Quad-A.”  Because the adoption of IPv6 has been slow, many domains have both IPv4 and IPv6 addresses. An example for Google can be found below:

  • IPv4 address for google.com is 127.217.11.174
  • IPv6 address for google.com is 2607:f8b0:4007:80d:0000:200e

Most operating systems are dual-stacked, meaning that they support both IPv4 and IPv6 simultaneously and the system will choose which address to access.

Similarities Between IPv4 and IPv6

Not all devices are assigned IP addresses in the IPv4 and IPv6 pool in order to gain access to the Internet. In fact, some IP addresses are used for certain things like private networks.

3. Private Address Space

   The Internet Assigned Numbers Authority (IANA) has reserved the
   following three blocks of the IP address space for private internets:

     10.0.0.0        -   10.255.255.255  (10/8 prefix)
     172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
     192.168.0.0     -   192.168.255.255 (192.168/16 prefix)

You can learn more here.

No-IP Solutions

Latest Protocol Capabilities

The changes we have made to our dynamic DNS compatibility protocol allow for both A  and AAAA hostnames to be updated individually or dual-stacked.  We have also added functionality to send IPv6 updates through IPv4 systems.  By doing this, we have given developers the flexibility to offer Dynamic DNS services through their devices and software in whatever format best meets their use case. Please check out our updated integration page or contact our integration specialists to find out more about our Dynamic DNS API and how it now supports IPv6. Get started now by offering your customers DDNS with full support for A and AAAA records using our dynamic DNS API!

IP Detection

If you are looking to use our dynamic DNS compatibility protocol on devices not connected directly to the internet (i.e., devices behind NAT), the router may be assigning IP addresses locally.  These DHCP events may occur without the router external IP address actually changing. In this case, we have provided an IP detection service that can be implemented to check for IP address changes on these devices to keep them connected to a hostname. To find out more, please visit our IP Detection Service page.

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Questions? Feel free to reach out to our awesome Customer Support team here.

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