What are IPV6 Unicast Addresses in computer networks?

Internet protocol version 6(IPv6) allows data transfer to take place over the network. The need for IPv6 arises as this protocol can handle the packets more efficiently which thereby improve the performance and security. Most importantly it enables the service providers to reduce the size of their routing tables.

Representation of IPv6

IPv6 consists of 128 bits which are represented by eight groups of hexadecimal digits out of which each group is represented by 16 bits that are separated by colons.

Example of IPv6 address


Types of IPv6

They are broadly classified into three types namely −

  • Unicast − From the name uni it’s so obvious that unicast is used for a single interface. So when the device sends the packet to a unicast address what happens is that the packet goes only to that specified interface that is being identified using the address.

  • Multicast − Multicast address identifies a set of interfaces belonging to different nodes. Here when the packet is being sent to the multicast address, the device over here broadcasts the packet to the interface by address.

  • Anycast − Anycast is similar to multicast address but here it identifies a set of interfaces that belong to different nodes. Also in Anycast the packets are being sent only to one interface and the rest of the process carried out is similar to that of multicast.

Unicast Addresses

To enable a router as IPv6 router, the unicast global configuration command must be used. SLAAC is Stateless Address Auto configuration is a method that allows obtaining address information, prefix length, and default gateway address information from a router without use of DHCPv6 server.

The common difference between the static and the dynamic addressing is that the static address does not change whenever a device is assigned a static IP address whereas dynamic IP address is assigned by the network and changes over time.

The following types of addresses are unicast IPV6 addresses −

  • Global unicast − Global unicast addresses are similar to public IPV4 addresses. It can be aggregated or summarized to produce an efficient routing infrastructure.

  • Link-local − Nodes use link-local addresses when communicating with neighbouring nodes on the same link, and are also called as a subnet.

  • Loopback − In loopback an address not assigned to any physical interface which can be used for a host to send an IPv6 packet to itself.

  • Unspecified address − It is used only as a source address and represents the absence of an IPv6 address.

  • Unique local − It is similar to a private address in IPv4 and not intended to be routable in the IPv6 Internet.

  • IPv4 embedded − An IPv6 address which carries an IPv4 address in the low-order 32 bits of the address.

Updated on: 13-Sep-2021


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