Differences between IPv4 &IPv6 (Performance & Security)

2021-02-18 05:11:17 ipv4 ipv6

An IP address is a string of numbers that is assigned to a device to identify it on the internet. It is an address, just as the number and street of your home is an address. While your home address is used to send you mail, your IP address is used to send packets of data that you request. There are 2 types of IP addresses, IPv4 and IPv6. Although they have the same functions, there is a significant difference between them. Read below to know more.

What is IPv4?

IPv4 stands for Internet Protocol version 4. It is the underlying technology that makes it possible for us to connect our devices to the web. Whenever a device accesses the Internet, it is assigned a unique, numerical IP address such as
To send data from one computer to another through the web, a data packet must be transferred across the network containing the IP addresses of both devices. It was originally thought that IPv4 could provide IP addresses for all devices on the internet, but it soon became apparent that a more robust alternative was needed to meet future demand, even if IPv4 addresses could be reused.
With the number of devices accessing the internet already numbering in the billions, especially since smartphones and the Internet of Things have become ubiquitous, almost all IPv4 addresses have been assigned — enter IPv6.

What is IPv6?

IPv6 is the next-generation Internet Protocol (IP) address standard intended to supplement and eventually replace IPv4, the protocol many Internet services still use today. Every computer, mobile phone, home automation component, IoT sensor, and any other device connected to the Internet needs a numerical IP address to communicate between other devices.
The original IP address scheme, IPv4 address is exhausted due to its widespread usage from the proliferation of so many connected devices. In addition to increasing the supply of IP addresses, IPv6 also addressed IPv4’s many shortcomings — chief among them being security, which we’ll delve into more later.

Differences between IPv4 and IPv6
IPv4 vs IPv6

The advent of IPv6 brought more functionality, in addition to more IP addresses. For example, IPv6 supports multicast addressing, which allows bandwidth-intensive packet flows (such as multimedia streams) to be sent to multiple destinations simultaneously, reducing network bandwidth. But is IPv6 better than IPv4? Let’s find out.
Speed comparison
How do IPv4 and IPv6 compare when it comes to speed? The security blog Sucuri ran a series of tests on IPv4 and IPv6 server performance in which they found that indirect connections, IPv4 and IPv6 delivered the same speed. IPv4 occasionally won the test.
In theory, IPv6 should be a little faster since cycles don’t have to be wasted on NAT translations. But IPv6 also has larger packets, which may make it slower for some use cases. What makes a difference at this point is that IPv4 networks are mature and thus highly optimized, more than IPv6 networks. Hence, with time and tuning, IPv6 networks will get faster.

Security comparison

IPv6 was built with more security in mind. IP Security (IPSec) is a series of IETF security protocols for security, authentication, and data integrity, and it’s fully integrated into IPv6. The thing is, IPSec can also be fully integrated into IPv4. It’s up to ISPs to implement it — and not all companies do.

1. IPv4 Security

IPv4 has been significantly updated over the years, so the difference between IPv4 and IPv6 security is not extraordinary. The same IPSec in IPv6 is now available for IPv4; it’s up to network providers and end-users alike to embrace and use it — so a properly configured IPv4 network can be as secure as an IPv6 network.
IPv6 is designed for end-to-end encryption, so in theory, widespread adoption of IPv6 will make man-in-the-middle attacks significantly more difficult.
IPv6 also supports a more secure name resolution. The Secure Neighbor Discovery (SEND) protocol adds a security extension to the Neighbor Discovery Protocol (NDP), which handles the discovery of other network nodes on a local link. By default, NDP is not secure, so it can be susceptible to malicious interference. SEND secures NDP with a cryptographic method that is independent of IPsec.

Thanks to native IPSec, IPv6 provides two security headers that can be used separately or together: The Authentication Header (AH) and Encapsulating Security Payload (ESP). Authentication Header provides data-origin authentication and protection against replay attacks, while ESP delivers connectionless integrity, data origin authentication, protection against replay attacks, and limited traffic flow confidentiality, as well as privacy and confidentiality through encryption of the payload. IPv4 can also have this protection if IPSec is implemented on the network.

2. IPv6 Security

IPv6 has a new feature called auto-configuration, which allows a device to generate an IPv6 address as soon as it powers up and puts itself on the network. The device begins by looking for an IPv6 router. If one is present, the device can generate a local address and a globally routable address, allowing access to the wider internet. In IPv4-based networks, the process of adding devices often has to be done manually. IPv6 allows devices to stay connected to several networks simultaneously. This is due to interoperability and configuration capabilities that enable the hardware to automatically assign multiple IP addresses to the same device.

Next, we will examine the differences between IPv4 and IPv6 through the lenses of speed and security.




Size of the address

32 bits

128 bits

Addressing method

IPv4 is a numeric address. It uses a dotted notation to
separate the binary octets.

IPv6 is an alphanumeric address. It uses a colon to
separate the binary bits.

Number of classes

There are five classes, A to E.

It allows a limitless number of IP addresses.

Type of addresses

Unicast, multicast, broadcast

Unicast, multicast, and anycast

Number of header fields



Length of header filed



Checksum fields

Has checksum fields

Has no checksum fields

Packet size

The minimum packet size for an IPv4 is 576 bytes.

The minimum packet size for an IPv6 is 1208 bytes.


IPv4 uses the address resolution protocol (ARP) to map an
IP address to the media access control (MAC) address.

IPv6 uses the neighbor discovery protocol (NDP) to map the
IP to MAC address.

Dynamic host configuration server (DHCS)

Clients request the DHCSs’ for IP addresses before
connecting to the network.

Clients have permanent addresses. There is no need for

Simple network management protocol (SNMP)

IPv4 uses SNMP for system management.

IPv6 does not use SNMP

Compatibility with mobile devices

IPv4 uses a dot-decimal notation, which is not appropriate
for mobile networks.

IPv6 uses hexadecimal colon-separated notation, which is
more appropriate for mobile networks.

Local subnet group management

IPv4 uses the internet group management protocol (GMP)

IPv6 uses multicast listener discovery (MLD).

Interoperability and mobility

It limits network topologies, therefore, hindering
interoperability and mobility.

It has interoperability and mobility capabilities embedded
in network devices.

Subnet mask

The designated network uses the subnet mask from the host

It does not use subnet masks.

Routing information protocol (RIP)

IPv4 supports RIP

IPv6 does not support RIP

Address features

IPv4 uses the network address translation (NAT) that allows
a single address to mask multiple non-routable addresses.

IPv6 uses direct addressing due to its vast address space.


Security depends on the applications.

IPv6 has an internet protocol security (IPsec) built into
the protocol to provide automatic security.

Optional fields

Has optional fields

It has no optional fields. It offers extension headers.


IPv4 and IPv6 play the same roles in the network, although there are differences in their performance, they still help us to connect with the network. If you need IPv4 or IPv6 in your business, we are leasing IPv4, IP brokers to help you buy IP address, and provide IPv6 trainingplease leave your contact below or live chat with our specialists at the right bottom.

- Written by Lotty Chen, Sourcing Executive at LARUS