2. Agenda
Why we need IPv6
The length of IPv6
Features of IPv6
Header Comparisons
How can I write IPv4 to IPv6
How to subnet IPv6
3. What is IPv6?
IPv6 is the abbreviation for Internet Protocol version 6. We
are currently on Internet Protocol version 4, or IPv4, but IPv6
will be the next generation protocol for Internet
communication. Not only will IPv6 provide a much larger
address space, but it will also provide features such as
improved routing traffic and better security.
4. Why do we need IPv6?
The Internet has experienced a phenomenal increase of
devices accessing the Internet. Because of this increase,
IPv4 addresses are running out. The solution is for IPv6 to
accommodate this increased demand by providing a much
larger address space, along with improved traffic routing and
better security.
5. Some of the advantages of
IPv6 are:
Larger IP address space: IPv6 has 128-bit address space or 4
times more address bits compared to IPv4's 32-bit address space.
This large address space will provide enough address space for
many decades to come. In real terms, every residential or
commercial customer will be able to receive more address space
from TWC than the entire IPv4 address space contains – several
billion IP addresses!
6. Better optimization:
IPv6 takes the best of what made IPv4 successful and gets rid of
minor flaws and unused features
7. Why we need IPv6
INTERNET world’s largest public data network, doubling in size
every nine months
IPv4, defines a 32-bit address - 232 (4,294,967,296) IPv4 addresses
available
The first problem is concerned with the eventual depletion of the IP
address space.
Traditional model of classful addressing does not allow the address space
to be used to its maximum potential.
8. Features of IPv6
Larger Address Space
Aggregation-based address hierarchy
– Efficient backbone routing
Efficient and Extensible IP datagram
Stateless Address Autoconfiguration
Security (IPsec mandatory)
Mobility
9. The Length of IPv6
128-bit IPv6 Address
3FFE:085B:1F1F:0000:0000:0000:00A9:1234
8 groups of 16-bit hexadecimal numbers separated by “:”
Leading zeros can be
removed
3FFE:85B:1F1F::A9:1234
:: = all zeros in one or more group of 16-bit hexadecimal numbers
10. Header comparison
the length of the ipv6 header in bytes
On the Internet, data is transmitted in the
form of network packets. IPv6 specifies a Removed (6)
new packet format, designed to minimize • ID, flags, flag offset
packet header processing by routers.
• TOS, hlen
• header checksum
Changed (3)
• total length => payload
• protocol => next header
• TTL => hop limit
20
bytes
40
bytes
Added (2)
• traffic class
• flow label
Expanded
• address 32 to 128 bits
11. Major Improvements of
IPv6 Header
No option field: Replaced by extension header. Result
in a fixed length, 40-byte IP header.
No header checksum: Result in fast processing.
No fragmentation at intermediate nodes: Result in fast
IP forwarding.
12. IPv6 Address with an Embedded IPv4
Address
IPv4-compatible IPv6 address is a special unicast IPv6 address used
by transition mechanisms on hosts and routers to automatically
create IPv4 tunnels to deliver IPv6 packets over IPv4 networks.
Address is made up of six high-order fields of 16-bit hexadecimal
values, represented by X characters, followed by four low-order fields
of 8-bit decimal values (IPv4 address), represented by d characters
(for a total of 32 bits).
13. IPv6 Address with an Embedded IPv4
Address
Two kinds of IPv6 addresses have an embedded IPv4
address:
1. IPv4-compatible IPv6 address
Used to establish an automatic tunnel to carry IPv6 packets
over IPv4 networks.
related to a transition mechanism of the IPv6 protocol.
2. IPv4-mapped IPv6 address
Used only on the local scope of nodes having both IPv4 and
IPv6 stacks.
Nodes use IPv4-mapped IPv6 addresses internally only.
These addresses are never known outside the node itself and
should not go on the wire as IPv6 addresses.
14. IPv6 Address with an Embedded IPv4
Address
IPv4-compatible IPv6 address
IPv4-mapped IPv6 address
15. IPv6 Addressing
128 bits (or 16 bytes) long: four times as long as its
predecessor.
2128 : about 340 billion billion billion billion different
addresses
Colon hexadecimal notation:
addresses are written using 32 hexadecimal digits.
digits are arranged into 8 groups of four to improve the readability.
Groups are separated by colons
2001:0718:1c01:0016:020d:56ff:fe77:52a3
16. HOW TO Subnet IPv6
First some background… an IPv4. IPv6
address is comprised of eight (8) blocks of four
hexadecimal digits separated with a colon “:”.
Each digit can be either a number [0-9] or a
letter [a-f] for a total of 16 possible
combinations per digit. 164 (yes this should be
written 216) gives 65,536 possible combinations
per block. The double colon “::” abbreviation is
commonly used in place of all zeros. This
double colon can only be used once while
specifying and address.