okay well we're going to focus on in
this video is the ending process or the
aaand ing ending process what happens
when we are in a network the devices if
when a device receives an IP address and
subnet mask and it's at the layer 3
because we know that the layer three
handles the IP addressing and that
device receives an IP address with the
subnet mask and in this case we're going
to look at 192 . 168 10 not 50 / 27 that
network devices I've got an IP address
and let's just say that this is my
source
let's just say that this is my source IP
address and i want to send this to a
destination address
well the device needs to know is this a
local is is the source and the
destination on the same network or is it
on separate networks and if its own
separate networks we have to do some
type of routing or can we just send this
local so what happens is the device uses
binary it works at the binary level 2
and or use the ending process so what
we're going to do is we're going to look
at what the device does it reads the IP
address in in in the binary mode so it
reads 1100 I've already written all this
out so that we have this here for us and
then what happens is the subnet mask
gets converted to binary and so i'm just
going to write this out here and we know
that the subnet mask is 255 255 . 255
and if you followed my subnetting video
you know that I always write this chart
out right here and this chart shows us
the subnet mask the bit places the host
minus to tell us how many hosts person
per subnet we can get and how many subs
we can get by using that last octet to
submit it out
so in this case we know we borrowed
three bits because this is a / 27 and we
borrowed three bits so we're going to
make that a subnet mask of 224 so . 224
for last subnet and we write that on
binary we know 255 is eight bits so I'm
just going to match all these up here
1234567 got too many and they're
123456789
we've got too many
they're so when I wrote this out I did
too many and let's swap this out here
and we will just fix this
quick get in a hurry
okay so we'll just say that's eight bits
there so we had to swap him back out
here so we have eight bits 12345678 and
the reason I'm doing this in handwriting
is because when you are on an exam
you're not going to have a calculator so
you're going to have to write this out
by hand on a whiteboard two three four
five six seven eight and so you need to
get used to practicing this by using a
pen and paper or a whiteboard or a dry
erase board with a marker and on the
last one here we've got our IP address
here in our first number are 224 we know
that's three bits so we just turn on our
first three bits here 11 100000 and then
what we do is the device it takes the IP
address and it ends it to the subnet
mask so the rule is if you have a
one-to-one you're always going to get a
1 and so I'm going to do green here
let's let's do it let's go this here so
if i get 1 of 1 i'm going to get a 1 and
then if i get a one-to-one I'm gonna get
a 1 and then 000000 because notice here
i have a one-to-one gives me a 10 and a
1 gives me a 0 or a 1 0 gives me a zero
so i'm going to do 10 10 10 00 . 0000 10
10 . and what I want to point out to you
real quick as if you if you notice this
because my IP address has a subnet of
255 on each of these debts
it's the ending number is going to be
the exact same as IP address so you can
really short cut this if you know your
subnet is in the last octet you don't
really have to end the first three out
tests
the device is going to it's going to add
those numbers together but you don't
have to do that you really are only
concerned if you're trying to find the
network ID of this subnet or is it on
the same subnet you really only have two
and the last subnet are the excuse me
the last octet on this subject are on
this IP address so if we do 00100000 we
can look up at our chart real quick and
we know that the third digit is 32 on
our binary chart so we know the ending
number is going to be 192 . 168 . 10 and
notice that's the exact same numbers are
IP address because it's on the same
network because of our subnet mask but
now this one is not 32 so our IP address
is not 50 we now know that our network
address is . 32 so we know that anything
in the . 32 or that's our network
address and if you watch my videos you
know that if you use this chart right
here that if we use the third bit place
we increment our subnets by 32 so we can
get our next subnet so if we need to
figure out what our broadcast ideas and
our host range we can just say 32 we're
going to increment by 32 so 32 plus 32
is 64 so we know this is the network ID
of the next subnet so we can just draw a
chart out and we can say our first
usable host is 33 and we can draw a
little line here and we can say one less
than 6463 so we know that this is the
broadcast ID for this subnet and then 62
is our last usable host on there so if
you've done setting on my other video
you know that this is a quick and easy
chart that I use so now we know that 192
. 192 168 . ten . 32 is on the same
subnet as . 50 because that's a network
ID so network ideas . 32 for $MONEY . 50
so everything from not 30 32 . 62 is on
the same subnet so if my destination IP
address is 33 through 62 this is going
to get sent local it but if it's outside
of that
let's say that this number is let's say
because this was going to be 65
and we know that's 4 plus 2 66 that's
gonna be 96 for the next one and let's
just subnet this down one more here and
we know that this is 95 and we know that
this is 94 so we know the next subnet
range so if we get a if we get a
destination IP address of 66 192 168 .
ten . 66 we know that it's going to go
into the routing process and that device
knows them
hey I need to route this to a point of
network of . 64 whatever that IP address
is whatever that link address has been
set inside the . 64 subnet and that's
the ending process the device takes the
IP address the device takes the IP
address it and the subnet mask together
and it gets the network address and it
knows what's radical at that point
because of because of the calculations
it knows it's in this isn't in the 27
bit range it knows that increments by 32
and it knows what other IP addresses are
in that subnet and that's simply how you
do ending