IPv6 Address: Public vs Private
As we know, every networking device must have an IP address to access the Internet. The IPv4 address space has been exhausted because many wireless and network-attached devices are joining the Internet rapidly on a daily basis. Therefore IPv6 is developed to create more unique IP addresses for these devices. The IPv6 address is similar to IPv4 in concept, but it provides far more than enough unique IP addresses for worldwide networking devices such as computer, router, data switch, etc. This is now a detailed introduction on what an IPv6 address is, and discuss differences between public and private IPv6 addresses. For more information on differences between IPv6 and IPv4, please read IPv4 vs IPv6: What’s the Difference?
IPv6 is short for Internet Protocol Version 6, which is the latest version of the Internet Protocol (IP). Like IP, IPv6 is a packet-based protocol used for exchanging data, voice, and video traffic over the digital network. It uses 128-bit addresses and provides about 340 undecillion IP addresses. As shown in the following figure, IPv6 consists of eight numbered strings, each containing four characters (alphanumeric), separated by colon.
IPv6 supports three address types: unicast, multicast, and anycast. Unicast IPv6 address allows a packet delivered to one interface. When it comes to the multicast IPv6 address, the packet is delivered to multiple interfaces. Anycast IPv6 address makes a package delivered to the nearest of multiple interfaces (in terms of routing distance). Among them, unicast and multicast IPv6 addresses support address scoping, which identifies the application suitable for the address.
Both public and private addresses exist in IPv6, but they are totally different in definition and application.
A public IPv6 address is an IP address which is accessible by anyone on the Internet. To avoid upsetting the order, the public IPv6 address is often globally unique. It can only be assigned to a unique device such as a web server, an email server or any server device directly accessible from the Internet. Therefore the public IPv6 address is usually provided by the Internet Service Provider (ISP).
Taking up a small part of the massive IPv6 address space, the private IPv6 is for special requirements and private use in IPv6 networks. These private IPv6 addresses are only local to a specific link or site, therefore they are never routed outside a particular network. Based on their scope, private IPv6 addresses can further be divided into site-local and link-local addresses. The site-local address has the scope of an entire site or organization. Link-local address, on the other hand, has a smaller scope and only refers to a particular physical link.
When we have a look at them we realize that the main difference between public and private IPv6 addresses lies in their scopes. To more concise, the public IPv6 address looks at a global scope, while the private IPv6 address is for a local network. Due to this, public and private IPv6 addresses also have the following differences:
|Public IPv6 Address||Private IPv6 Address|
|Connected with the Internet network||Connected with a LAN|
|Publicly registered with Network Information Center||Is not registered with Network Information Center|
|Requires Modem to connect to a network||Requires network switch to connect to a network|
|Assigned by the ISP to identify a home or business network from the outside||Allotted by the client and are given by the client’s switch such as a Gigabit Ethernet switch|
Now many ISPs, websites and manufacturers are supporting IPv6, and we will be inevitably switching to an IPv6 address. When preparing your network for IPv6, do not forget to use the IPv6 compatible hardware and software, especially network switches supporting IPv6 forwarding. FS provides a series of 1G and 10G switches that support both IPv4 and IPv6 addresses. They also comprise of advanced features including MLAG, SFLOW, SNMP, etc. For more information, please visit our website www.fs.com.
Related Articles:How to Understand IP Address and Subnet Mask? DHCP vs Static IP: What’s the Difference? DHCP and DNS: What Are They, What’s Their Difference?