IPv6

Computers use special names to find each other. These names help them talk on the internet.

We used to run out of these names. There were not enough for every device.

A new system was made to help. It gives us many more names.

This new system is called IPv6. It can make many, many more names.

Now, more things can join the internet. It helps us stay connected. This is a great way to grow!

Computers on the internet need special names to find each other. These names are called IP addresses. They act like a home address for your device.

For a long time, we used a system called IPv4. IPv4 uses 32-bit addresses. This means it can only make about 4.3 billion names.

As more people joined the internet, we began to run out. By 2019, one group said they had no more IPv4 addresses left.

To fix this, experts made a new system called IPv6.

This system uses 128-bit addresses. Because the names are much longer, it can make a huge number of them. It can make 340 undecillion addresses! That is a number so big it is hard to imagine.

IPv6 also helps the internet work better. It makes it easier for routers to move data. Routers are parts of the network that direct traffic. IPv6 also lets devices set up their own names automatically. It can even make temporary names to help keep your privacy safe.

Every device on the internet needs a way to be found. This is done using an Internet Protocol, or IP address. Think of an IP address like a digital home address. It identifies where a computer is located on a network. It also helps route traffic across the vast internet. Without these addresses, devices could not talk to each other. IPv6 is the newest version of this important system.

How does this new system work so well? IPv6 uses 128-bit addresses to identify devices. This is much larger than the older 32-bit system. Because the addresses are longer, the system can make a huge number of them. In fact, it can create 340 undecillion addresses.

These addresses look like eight groups of four hexadecimal digits. Each group is separated by a colon. This large space allows for many special features. For example, it makes it easier to manage how data travels through routers.

Experts had to create IPv6 because the old system was running out. The older version is called IPv4. It was first used as a research project by DARPA.

IPv4 could only provide about 4.3 billion addresses. As the internet grew in the 1990s, people realized this would not be enough. By 2011, the last large blocks of IPv4 addresses were handed out. In November 2019, a group called RIPE NCC announced they had run out completely.

To solve this, the IETF developed IPv6.

IPv6 does more than just provide more names. It makes the internet run more smoothly. One way is through multicast addressing. This lets a device send one packet to many destinations at once.

It also helps with device mobility and security. Devices can even set up their own addresses automatically. This is called stateless address autoconfiguration, or SLAAC. To protect your privacy, devices can create temporary addresses. These random addresses change often so you are harder to track.

You can think of IPv4 like a small town with limited street names. Once every house has a name, no new houses can be built. IPv6 is like a massive, endless galaxy of names.

It ensures that every new gadget, phone, or computer can always have its own unique spot. Even though IPv4 and IPv6 do not work together directly, they can coexist. This helps the world slowly move from the old way to the new way. This transition keeps our global network growing and connected.

Internet Protocol version 6, or IPv6, is the most recent version of the Internet Protocol (IP). This is a communications protocol that provides an identification and location system for computers on networks. It is essential because it routes traffic across the Internet. Every device on the Internet is assigned a unique IP address for identification. As the Internet grew rapidly after its commercialization in the 1990s, engineers realized the existing system could not support enough devices. IPv6 was developed by the Internet Engineering Task Force (IETF) to solve the problem of IPv4 address exhaustion. It was intended to replace the older version, IPv4, to ensure the global network could continue to expand.

The mechanism of IPv6 relies on a much larger addressing space than its predecessor. While IPv4 uses 32-bit addresses, IPv6 uses 128-bit addresses.

This change yields a massive address space of 2^128, which is approximately 340 undecillion total addresses. An IPv6 address is represented as eight groups of four hexadecimal digits each. These groups are separated by colons. For example, a full address can be shortened using specific rules to make it easier to read. Because the address space is so large, the network identifier part is usually 2^64 addresses. This makes the subnet size about four billion times larger than the entire IPv4 address space.

IPv6 uses different types of transmission to move data. The architecture allows for three distinct types: unicast, anycast, and multicast.

Unicast involves sending a packet to a single specific destination. Multicast allows a single packet to be sent to multiple destinations at once. IPv6 expanded and simplified multicast addressing to provide better optimization for service delivery. Interestingly, IPv6 does not implement traditional broadcast, which sends a packet to every host on a link. Instead, it uses a specific link-local all-nodes multicast group to achieve a similar result. This design helps make the delivery of data more efficient across different networks.

The history of these protocols began with IPv4, which was originally a research project by DARPA. DARPA is a United States Department of Defense agency. IPv4 provided approximately 4.3 billion addresses, which seemed sufficient at first. However, as the Internet became a global tool, these addresses became scarce.

By February 2011, the last unassigned top-level blocks of 16 million IPv4 addresses were allocated by the Internet Assigned Numbers Authority (IANA). Eventually, the five regional Internet registries, or RIRs, reached a stage where they could only provide very small blocks of addresses. RIPE NCC, one of these registries, announced it had fully run out of IPv4 addresses on 25 November 2019.

This exhaustion made the transition to IPv6 a critical necessity.

IPv6 provides several technical benefits that improve how routers process data. The IPv6 packet header is designed to be simpler than the IPv4 header.

This simplicity minimizes the processing work required by routers when they forward packets. Many rarely used fields have been moved to optional header extensions. This allows routers to focus on the most important information. Additionally, IPv6 places the responsibility for packet fragmentation on the end points rather than the routers. This change further simplifies the work of the routers in the middle of a network. It also allows for hierarchical address allocation, which helps limit the expansion of routing tables across the Internet.

One important feature of IPv6 is Stateless Address Autoconfiguration, known as SLAAC. This allows hosts to configure themselves automatically when they connect to a network.

Every interface has a self-generated link-local address. Routers then provide network prefixes via router advertisements. This makes it much easier to manage a network. If a network changes its connectivity provider, IPv6 allows for easier renumbering. In IPv4, changing a network prefix is a major effort. In IPv6, changing the prefix announced by a few routers can renumber an entire network. This is possible because the host identifiers can be independently self-configured.

Security and privacy are also central to the design of IPv6. Because every device can have a unique, globally addressable IP address, tracking a device across networks becomes easier. This is a concern for mobile devices like cell phones. To help, the SLAAC protocol includes "temporary addresses" to protect privacy. These addresses are random and unstable. A typical device might generate a new temporary address every day. This makes it harder for others to track a specific device over long periods. Furthermore, while Internet Protocol Security (IPsec) was originally developed for IPv6, it is now a recommendation for many implementations. This helps ensure that devices from different vendors can still communicate securely.