IPv6 (Internet Protocol Version 6) is the most recent version of the Internet Protocol (IP). It was developed to address the limitations of the predecessor, IPv4.
Here are its key aspects in a concise form:
Larger Address Space: IPv6 uses 128-bit addresses, significantly expanding the number of available IP addresses compared to the 32-bit system of IPv4. This is crucial for accommodating the growing number of devices connected to the internet.
Address Format: IPv6 addresses are written in hexadecimal and separated by colons, for example, 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
Improved Routing and Network Autoconfiguration: IPv6 simplifies and streamlines routing. It also supports better automatic network configuration, making it easier for devices to join networks.
No Need for NAT (Network Address Translation): Due to the abundance of addresses, IPv6 eliminates the need for NAT used in IPv4 to conserve addresses, thereby simplifying networking and improving end-to-end communication.
Built-in Security: IPv6 was designed with IPsec, a suite of protocols for securing internet protocol communications by authenticating and encrypting each IP packet in a data stream.
Better Multicast and Anycast Abilities: It improves upon these capabilities compared to IPv4, aiding in the efficiency of data transmission to multiple destinations.
Transition Mechanisms: Various technologies, such as dual-stack, tunneling, and translation, are in place to facilitate the transition from IPv4 to IPv6.
As with the IPv4’s Unicast, Broadcast and Multicast addresses that define the basics of communication and connectivity on the internet, IPv6 managed to remove the broadcast (because of the difficulties it causes on a network through looping) from the trio and introduced Anycast.
Let’s look at these IPv6 address types in detail below:
Unicast Address: Packets addressed to a unicast address are destined for a single interface. This can also referred to as the –to-one ipv6 address. Other different type of unicast addressing is Global, Link-local, and Site-local.
Global Unicast Address: An IPv6 unicast address is globally routable on the public internet. It shares the same address format as an IPv6 anycast address. Global unicast addresses are assigned by the Internet Assigned Numbers Authority (IANA).
Link-local Addresses: These are the private address that is not meant to be routed on the internet. They can be used locally by private or temporary LANs for sharing and distribution of files among devices on the LAN.
Unique local address: This type of IPv6 address is also not intended to be routed on the public internet. Unique local is a replacement of site-local address, that allows communication within a site while being routable to multiple local networks.
Multicast Address: This can also be referred to as One-to-Many. Packets addressed to a multicast address are delivered to all interfaces identified by the multicast address. Multicast address types are easily notable because they normally begin with FF.
Anycast: This form of ipv6 address is similar to the multicast address with a slight difference. Anycast address can also be referred to as One to Nearest. It can be used to address packets meant for multiple interfaces, but usually, it sends packets to the first interface it finds as defined in the routing distance. This means it sends packets to the closest interface as determined by routing protocols.
Anycast address is a very special ipv6 addressing type such that it can also be used to deliver a packet to more than one interface which also helped earn the name as One-to-One or Many address!
Loopback Address: Just as in IPv4, a provision has been made for a special loopback IPv6 address for testing. However, in IPv6 there is just one address, not a whole block, for this function. The loopback address is 0:0:0:0:0:0:0:1, which is normally expressed using zero compression as “::1“.
Special IPv6 addresses
Just like in IPv4, IPv6 has some addresses specially reserved for specific use. Below are examples of these addresses:
1. 0:0:0:0:0:0:0:0 can be represented as ::
This is equivalent to the ipv4 version of 0.0.0.0.which is the host source address used during stateful configuration.
2. 0:0:0:0:0:0:0:1 = 1 – This is 127.0.0.1 equivalent in IPv4.
3. 20000::/3 – The global unicast address range.
4. FEC00::/7 – The unique local address range.
5. FE80::/10 – Link-local unicast address range.
6. FF00::/8 – The multicast range.
7. 3FFF: FFFF::/32 and 2001:0DB8::/32 – Reserved address range for examples and documentation.
8. 2002::/16 – this address range are normally use during the ipv6 transition or migration(6to4) configuration.
Why We Need IPv6.
IPv6 Address Expression and Example. How IPv6 Address Works.
How to Configure IPv6 on Cisco Router. IPv6 Routing Protocols. Ways To Migrate To IPv6
