IPv4 vs IPv6 explained

Every internet user must have come across these two terminologies — IPv4 and IPv6.

What do they mean? How they differ from each other? Which one is better ? — Most of us have these kinds of questions about IPv4 and IPv6.

In this article, we are going to clear that up for you. Today you will learn the main difference between IPv4 and IPv6 and will find out which is better over other. We also provide a table of comparison of IPv4 vs IPv6.

What are IPv4 and IPv6?

IP (Internet Protocol) addresses are the codes used by machines to find each other on the internet. And IPv4 and IPv6 are two generations of Internet Protocol where IPv4 stands for Internet Protocol version 4 and IPv6 for Internet Protocol version 6.

IPv4 is a protocol for use on packet-switched Link Layer networks (e.g. Ethernet). It is one of the core protocols of standards-based inter-networking methods on the Internet and was the first version deployed for production in the ARPANET in 1983. IPv4 uses 32-bit source and destination address fields which limit the address space to 4.3 billion addresses. This limitation stimulated the development of IPv6 in the 1990s.

IPv6 is more advanced and has better features compared to IPv4. It has the capability to provide an infinite number of addresses. It is replacing IPv4 to accommodate the growing number of networks worldwide and help solve the IP address exhaustion problem. IPv6 was developed by the Internet Engineering Task Force (IETF).

IPv4 vs IPv6:

What is the difference between IPv4 and IPv6?: IPv4 vs IPv6

One of the main difference between IPv4 and IPv6 is their address space. As we already said the size of an address in IPv4 is 32-bits. Where IPv6 address fields are 128-bits.

Because of their difference in address space — appearance of the IP addresses in IPv4 and IPv6 also looks different. In IPv4 IP addresses are appeared as four 1 byte decimal numbers, separated by a dot (eg: and in IPv6 IP addresses appears as hexadecimal numbers that are separated by colons (eg: fe80::d4a8:6435:d2d8:d9f3b11).

Clients using IPv4 addresses use the Dynamic Host Configuration Protocol (DHCP) server to establish an address each time they log into a network. This address assignment process is called stateful auto-configuration. IPv6 supports a revised DHCPv6 protocol that supports stateful auto-configuration, and supports stateless auto-configuration of nodes. Stateless auto-configuration does not require a DHCP server to obtain addresses. Stateless auto-configuration uses router advertisements to create a unique address. This creates a «plug-and-play» environment, simplifying address management and administration. IPv6 also allows automatic address configuration and reconfiguration. This capability allows administrators to renumber network addresses without accessing all clients.

These are the basic difference between IPv4 and IPv6.

Advanced differences between IPv4 and IPv6 :

IPv4 IPv6
 Packet size: 576 bytes required, fragmentation optional  Packet size: 1280 bytes required without fragmentation
 Packet fragmentation: Routers and sending hosts  Packet fragmentation: Sending hosts only
IPv4 has a lack of security.
IPv4 was never designed to be secure
– Originally designed for an isolated military network
– Then adapted for a public educational & research network.
 IPv6 has a built-in strong security
– Encryption
– Authentication
 IPv4 header has 20 bytes.
IPv4 header has many fields (13 fields)
 IPv6 header is double, it has 40 bytes.
IPv6 header has fewer fields, it has 8 fields.
 ISP have IPv4 connectivity or have both IPv4 and IPv6  Many ISP don’t have IPv6 connectivity
 Non-equal geographical distribution (>50% USA)  No geographic limitation

So which one is better? — IPv4 or IPv6

Since IPv4 has been around here for a long time, but when comes to security IPv6 holds the stakes. Almost every big websites like Google, Facebook, YouTube, Wikipedia..etc all are now using IPv6.

So what made them migrate to IPv6? And why should every business deploy IPv6? So here are the major advantages of IPv6 over IPv4.

Advantages of IPv6 over IPv4

  • Inevitability — As we all know IPv6 will soon be the only option for adding new devices or hosts on the internet.
  • Efficiency — IPv6 eliminates most of the address conflict issues common under IPv4 and allows more streamlined connections and communications for devices.
  • Security — One of the most important factors is security. IPv6 encrypts and checks packet integrity to provide VPN-like protection for standard internet traffic.
  • IPv6 simplified the router’s task compared to IPv4.
  • IPv6 is more compatible with mobile networks than IPv4.
  • IPv6 allows for bigger payloads than what is allowed in IPv4.
  • IPv6 is used by less than 1% of the networks, while IPv4 is still in use by the remaining 99%.

Daily a vast number of websites are being created and as more and more websites are deployed, the number of IP addresses needs to increase correspondingly. Not only websites, more than 4 billion devices already share addresses. And in future more devices like smartwatches, fridges and cars will need IP addresses. Unfortunately, the original specification for IP address (IPv4) will not serve our needs in the future, so we need to move over to IPv6, which will allow the creation of more online contents and more connectivity between the machines.


  1. The full form of the IP is Internet Protocol. It describes the technical format about how data packets are processed and communicated in the network with the help of the addressing scheme of computers. Almost all Network IPs are also known as Transmission Control Protocol (TCP), which are called the Transmission Control Protocol (TCP), by connecting with the IP, the virtual connection creates a destination connection between the destination and the source.


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