- [Instructor] In this segment,
we're gonna take a closer look at IP version six addressing,
but we're gonna start with review of IP version four.
Now, an IP version four address is made up of 32 bits.
It's binary ones and zeros
divided into four eight bit blocks.
So for example, we have the binary here, 32 bits
and you can see that they are broken up
into the four eight bit blocks.
But you and I know
that that's not how we actually refer to an IP address.
We refer to an IP address
in a dotted decimal format, for example, 10.5.6.205.
So the question is how did we get it
from that binary to that decimal format?
Well, we do that by doing a conversion,
converting binary to decimal.
The way we do that is in each eight bit block,
a value is assigned to each of the places.
So starting over on the right hand side,
the values are one, two, four, eight,
16, 32, 64, and 128.
And in each block, a zero represents null or no value
and a one says that we pick up the value of that place.
So let's do a conversion together.
Let's start with converting 00001010.
Well, let's start over on the left hand side
A zero tells us there's no value,
so we're not gonna pick anything up in the 128 place
or in the 64 or in the 32 or in the 16.
But a one indicates that we do pick up
the value of that place.
So we're gonna pick up the value of eight.
There's a zero in the four, so no value.
We are gonna pick up the value of two
and there's a zero in the one.
So eight plus two is going to give us a decimal value of 10.
Let's do one more.
Let's do the one all the way up to the right.
That block is 11001101.
Remember, a zero represents no value or a null.
A one says we pick up the value of that place.
So we have a one in the first place here,
so we're gonna pick up 128.
We're going to pick up 64.
We have a zero in the 32, so nothing there.
A zero in the 16, nothing there.
A one in the eight place,
so that means we'll pick up the eight.
A one in the four place,
so we'll pick up the four.
A zero in the two and then a one in the one place.
So we're gonna take 128 plus 64, which is 192.168.10.0,
plus eight is 200, plus four is 204 plus one is 205,
which is gonna give us a decimal format of 205.
If we were to do all of them,
we would end up with a 10, a five, a 60,
and 205 is our values
and we separate them with a period or a dot.
That's how we get our dotted decimal format.
Well, IP version six does not use decimal
or dotted decimal notation.
Instead it uses hexadecimal
and instead of dots it's going to separate using a colon.
So let's first talk about what hexadecimal is
and then we'll take a look at IP version six addresses.
Hexadecimal is a positional numbering system
that uses base 16.
To represent the values in a readable format,
the system uses the number zero to nine
to represent the values from zero to nine
and the letters A to F to represent the values
from 10 to 15.
So if you look at our table here, we have decimal,
binary, and hex, and I've given you
a little binary cheat sheet
of those first four positions over to the right
of one, two, four, and eight.
So we know decimal zero is binary 000,
it's also hex zero.
How about decimal one?
Well in binary, that would be represented by 0001,
only having the one place,
and in hex it's gonna be a one.
Let's jump down to nine.
Nine in decimal is 1001 in binary.
Picking up the eight place plus the one is nine.
And it will still be nine in hex
because we're going to use zero to nine
to represent the values from zero to nine.
Now let's go to 10.
Right, 10 in decimal is one zero or 10.
In binary it's 1010, representing the eight place
and the two place.
Eight plus two is 10.
And it's going to be represented by the letter A in hex.
Jumping down to 15.
15 in decimal.
Binary it's 1111,
which is eight plus four plus two plus one.
So eight plus four is 12, plus two is 14, plus one is 15,
and that's gonna be represented by the F.
So now let's take a look at how IP version six addressing
actually uses hex, how we do a conversion,
and then we'll look at some rules
to make it a little bit simpler.
An IP version six address is made up of 128 bits
divided into eight 16 bit blocks.
If we compare and contrast that
to a IP version four address,
well IP version four was going to be 32 bits,
this is 128 bits.
And IP version four had four eight bit blocks,
and now we have eight 16 bit blocks.
So this is what an IP version six address
is gonna look like in binary.
But we're not gonna convert it to dotted decimal.
Instead we're gonna convert it to hex.
So each block is going to be converted into
a four digit hexadecimal number
and we're going to separate those blocks by a colon symbol.
So let's just do one.
Let's take that last block which is 0101111011111001.
And what we're gonna do is we're gonna divide it
into four sections, so four, four bit sections,
so 0101, 1110,
1111 and 1001.
Again, it's this last block we're working with.
And then we're going to convert each of those into a hex.
So binary 0101 we know is going to be five, right,
because it's gonna be four plus one is five,
and five in hex is five.
Binary 1110 is gonna be 14, right?
Eight plus four is 12 plus two is 14.
Decimal 14 is going to be hex of E.
We come down here.
1111 in binary is going to be 15 in decimal.
Right it's gonna be eight plus four is 12
plus two is 14, plus one is 15,
and that's gonna be represented by F in hex.
And then nine is 1001, right,
that's decimal nine, right?
Eight plus one.
And nine is gonna be represented by nine in hex.
So that binary block, that 16 bit block,
when we divide it into four hexadecimal digits,
we're gonna end up with 5EF9.
And we converted this entire address from binary to hex.
Here is what our conversion would be,
which is better, but still pretty long.
So let's look at three rules to try to make
that even a more manageable address.
This is the address we're starting with right here,
and we're gonna again try to make it
a little bit more manageable.
Our first rule is we can discard leading zeros.
So we have 0063, We can discard the two leading zeros
and just end up with 63.
In rule two,
if two or more blocks contain consecutive zeros,
we can omit them all
and we can replace them with a double colon symbol.
And note, you can only do this once
so we have two blocks of four zeros, 0000:0000,
and what we can do is we can instead replace them
with the double colon.
And lastly, rule three, which is blocks of zeros
can be replaced only once with that double colon,
so if there are still blocks of zeros,
they can be shrunk down to a single zero.
So we have one more block here of the four zeros.
We can shrink it down to a single zero.
Which means in the end we could take
this relatively long address, right here,
and we can make it a little bit more manageable.
And now you know how to convert
from binary to decimal to hex,
and three rules for making our IP version six address
a little bit more manageable.
And that my friends
is a closer look at IP version six addressing.