IPv6 Global Unicast Address

Another important IPv6 address type is IPv6 Global Unicast Address. IPv6 Global Unicast Addresses are the globally routable and reachable IPv6 addresses over Internet which fall within the range 2000::/3. In other words, they are IPv6 Addresses of Internet. Like all IPv6 address types, this address type is also important in Cisco CCNA Certification Exam.

How to Configure IPv6 on Routers with Packet Tracer?

What is IPv6 Global Unicast Address?

Global Unicast Address is a routable IPv6 address that we use on Internet. It is similar to IPv4 Public IP Addresses. These addresses are assigned by IANA (Internet Assigned Numbers Authority).

There are many Global Unicast Address available that we can use on different devices even on the newly IP available Internet of Things (IoT) devices. All the connected devices need to have one of these public IPv6 global addresses. There is no IP address exhaust problem in the world after IPv6 addresses. So, we can assign an IPv6 GUA to these connected devices.

You Can Also Check Comparison of IPv4 versus IPv6!

What is IPv6 Global Unicast Address Range?

IPv6 Global Unicast prefix is 2000::/3. The high level 3 bits of this prefix are 001. This means that these addresses start with binary value 001. And the fourth bit can be 0 or 1. This means that, a IPv6 Global Address can start with hex digit 2 or 3 according to the value of the fourth bit. 

• 2000::/3
• 3000::/3

Here, the range of ipv6 global address is 2000::/3 to 3FFF::/3.

IPv6 Global Unicast Address Parts

In Global Unicast Address, there are different parts. The first 3 bits of these addresses are fixed. The binary form of these three bits is 001. The remaining parts are 45 bits Global Routing Prefix, 16 bits Subnet ID and 64 bits Interface ID.  Below, you can see these Ipv6 Global Address parts.

• 3 bits fixed part is 2000::/3 (0010).
• 45 bits are Global Routing Prefix is determined.
• 16 bits Subnet ID.
• 64 bits Interface ID.

Frequently Asked Questions

What is the Range of IPv6 Global Unicast Addresses?

IPv6 Global Unicast Addresses prefix is 2000::/3. This is the range between 2000:: to 3FFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.

What are the Main Parts of an IPv6 Global Unicast Address?

There are three main parts in a Global Unicast IPv6 Address. These parts are:

• Global Routing Prefix which Identifies the network assigned by an Internet Service Provicer (ISP).
• Subnet ID which used by organizations to create subnets.
• Interface ID which identifies a specific device on the network.

Who Allocates 2000::/3 Prefix to Regional Service Providers?

Internet Assigned Numbers Authority (IANA) allocates IPv6 2000::/3 prefix to the Regional Internet Registries like RIPE NCC, ARIN, APNIC, LACNIC, AFRINIC etc. These addresses are allocated to smaller ISPs from these Regional Internet Registries.

What is the difference between IPv6 Global Unicast and Link-Local addresses?

Global Unicast (2000::/3) Addresses are Public and routable IPv6 addresses on the internet while Link-Local (FE80::/10) Addresses only valid within a local network segment. The main purpose of Global Unicast addresses is the communication on Internet. On the other hand, Link-Local addresses are used for internal communication like neighbor discovery.

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