2. IPv6 Addresses
An Internet Protocol version 6 address
(IPv6 address) is a numerical label that is used
to identify a network interface of a computer or
other network node participating in an IPv6
computer network.
3. Structure
An IPv6 address consists of 16 bytes
(octets); it is 128 bits long
Hexadecimal Colon Notation
More readable
128 bit is divided into 8 sections ,each bytes in length
2 bytes in hexadecimal notation requires 4 hexadecimal digits
Address consists of 32 hexadecimal digits
Every 4 digits separated by a colon
5. Abbreviation
•Hexadecimal format is very long.
•Many of the digits are zeros.
•Leading zeros of a section can be omitted.
•Only leading zeros can be dropped ,not the
trailing zeros.
7. IPv6 has a much larger address space .
The designers of IPv6 divided the
address into several categories.
A few leftmost bits, called the type
prefix in each address define its category
Address Space
11. Unicast Addresses
A unicast address defines a single computer.
The packet sent to a unicast address must be
delivered to that specific computer.
IPv6 defines two types of unicast address:
Geo-graphically based
Provider-based
13. The provider-based address is generally used
by a normal host as a unicast address.
Prefixes for provider-based unicast address
14. Fields for the provider based are as
follows:
Type identifier:-
3 bit field
Address as the provider based address
Registry identifier:-
5 bit field
3 registry centers : INTERNIC ,RIPNIC
,APNIC
Provider identifier:-
16 bit field
15. (Continued….)
Subscriber identifier:-
24 bit field
when organization subscribes to the
internet through a provider ,it is assigned.
Subnet identifier:-
32 bit field
Defines a specific subnetwork under the
territory of the subscriber.
Node identifier:-
48 bit field
Defines the identity of the node
connected to a subnet
18. A packet sent to a multicast address must be
delivered to each member of the group.
Second field is a flag that defines the group
address , either permanent or transient.
A permenent group address is defined by the
Internet authorities and can be accessed at all
times.
A transient group address, on the other hand is
used only temporarily.
19. Anycast Addresses
Address is delivered to only one of the members
of the anycast group,the nearest one .
One possible use is to assign an anycast address
to all routers of an ISP that covers a large logical
area in the internet.
The router outside the ISP deliver a packet
destined for the ISP to the nearest ISP router.
No block is assigned for anycast addresses.
21. Reserved Addresses
• It start with eight 0s (type prefix is 0000 0000).
Reserved addresses in IPv6
22. An Unspecified address is used when a host
does not know its own address and sends an
inquiry to finds its address.
A Loopback address is used by a host to test
itself without going into network.
A Compatible address is used during the
transition from IPv4 to IPv6.
A Mapped address is also used during the
transition.
23. Local Addresses
It is used when an organization wants to use
IPv6 protocol without being connected to the
global Internet.
They provide addressing for private network.
24. Local addresses in IPv6
A link local address is used in an isolated subnet.
A site local address is used in an isolated site with
several subnet.
