IPV six was developed by the Internet Engineering Task Force IETF, I'm sure you look it up to deal
with the long anticipated problem of IPV for address exhaustion.
So IPV six is intended to replace IPV for.
IPV six became a draft standard in December 1998 and became an Internet standard on the 14th of July
2017.
So instead of 32 bit addressing of IPV four, which provides approximately four point three billion
addresses, IPV six uses a 128 bit address.
So that theoretically gives us to do the power of one hundred twenty eight or approximately three point
four times 10 to the 30th addresses.
Big number.
You can check my math later, but stick with me for now.
I mean, the actual number is slightly smaller, is multiple ranges are reserved for special use or
they're just completely excluded from use.
But with a rough calculation, the total number of possible IPv6 addresses is more than seven point
nine times 10 to the power of 28 times as many as IPV.
For the two protocols, IPV four and IPV six are not designed to be interoperable.
Complicating the transition to IPv6, however, several IPv6 transition mechanisms have been devised
to permit communication between IPV four and IPv6 hosts.
In addition to offering more addresses, IPV six also implements features not present in IPV for.
Simplified header.
IPV six is heter has been simplified by moving all unnecessary information and options which are present
in the IPV forever to the end of the IPV six header, the IPv6 header is only twice as big as an IPV
for header because that IPv6 address is four times longer.
End to end connectivity.
Every system now has a unique IP address and can traverse through the Internet without using that or
other translating components.
After IPV six is fully implemented, every host can directly reach other hosts on the Internet with,
well, with some limitations involved, like a firewall organization, policies and stuff like the.
Auto configuration.
IPV six boards, both stateful and state, less auto configuration mode of its host devices.
This way, the absence of a server does not put a halt on inter segment communication.
Faster forwarding and routing.
A simplified header put all unnecessary information at the end of the header, like we saw earlier,
the information contained in the first part of the header is adequate for a router to make its routing
decisions, thus making them as quickly as looking at the mandatory header.
IP, sec.
Initially, it was decided at IPV six must have SEC making it more secure than IPV for this feature
has now been made optional.
IP Internet protocol security is a framework of open standards for helping to ensure private secure
communications over Internet protocol networks, IP networks through the use of cryptographic security
services.
OPSEC is an end to end security scheme operating in the network layer, while some other Internet security
systems and widespread use to lessen S.H. operate in the upper layers, IP set can automatically secure
applications at the IP layer.
No broadcast.
Though Ethernet and token ring are considered a broadcast network because they support broadcasting,
IPV six does not have broadcast support anymore.
It uses multicast to communicate with multiple hosts.
Mobility IPV six was designed keeping mobility in mind, this feature enables hosts such as a mobile
phone to roam around in different geographical areas and remain connected with the same IP address.
The mobility feature of IPv6 takes advantage of auto IP configuration and extension headers.
Extensibility.
One of the major advantages of the IPV six header is that it is extensible, adding more information
in the option part.
IP V4 provides only 40 bytes for options, whereas options in IPv6 can be as much as the size of the
IPv6 packet itself.
What is the IPV six pack it you ask, you came to the right place.
And IPV six pack, it is the smallest message entity exchanged via the Internet protocol across an IPV
six network, but stay with me here.
The package consists of control information for addressing and routing and a payload consisting of user
data.
The control information in IPV six packets is subdivided in a mandatory fixed header and optional extension
headers.
The fixed header starts in IPV six packet and as a size of 40 octets, which means 320 bits, its format
is shown in the slide.
Version is constant six payload length is the size of the payload in bytes, including any extension
headers, Hopp limit replaces the time to live field in the IPV for.
Well, I think source, address and destination address fields are fairly obvious.
Extension headers carry optional Internet layer information and are placed between the fixed header
and the upper layer protocol header.
128 bit IPV six addresses are written using hexadecimal as opposed to dotted decimal back in IPV for.
Because a hexadecimal number uses four bit, this means that an IPV six address consist of 32 hexadecimal
numbers.
These numbers are grouped in fours, giving eight groups or blocs, the groups are written with a colon
as a separator.
And IPV six address example is shown in the slide.
So because of the length of the IPv6 addresses, various shortening techniques are employed, the main
technique being to omit repetitive zeros as shown in the example.
So as I mentioned before in IPV for an address is split into two components, right, network ID and
a host.
This was done initially using address classes and then later using subnet masking.
In the unicast addressing of IPV six, it's done in the same way.
The first step is to split the address into two parts addresses, split into two 64 bit segments.
The top 64 bits is a network ID and the lower 64 bits is the host ID.
The most significant 64 bits are used for routing, and the less significant 64 bits identify the address
of the interface or host.
This block is derived from the actual physical or MAC address in practice.
So if we look at the most significant 64 bits in more detail, we can see that it's split into two blocks
of 48 and 16 bits.
Now, the significant 16 bits are used for subnets on internal networks and are controlled by a network
administrator.
The most significant 48 bids are used for the global network addresses and are used for routing over
the Internet.