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>> In the Arizona, just about every house has
a pool, because it's so hot here all the time.
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So, one of the key things you have
to do is teach your kids to swim.
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And I've found that, it's-- you reach, you
know, different milestones in swimming,
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but the toughest one is to go from
the floaty thing down to nothing
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to where they're just in the pool.
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So, you know, your child will be standing on the
edge and you're like "Come on honey, jump in,"
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and, "No, I'm scared", and you're like, "No,
it'll be fine, I'm right here, just jump in."
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No I'm scared!"
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You just got to reach the point
where you get out of the pool,
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pick up the child and jog him in.
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You know, hey, wait, before you call
CPS, you go in with them, right?
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And you help them and they just got to tread
water a little while and then they get in.
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And then they'll like, "Oh, okay, this is kind
of fun," and you'll help him around the pool
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and all that kind of-- so,
subnetting is the same way.
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I have found that through, through many years
of teaching, rather than start off with, "Okay,
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well here's the con-- ," I
mean, you just got to jump in.
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You got to say, "Okay, here's the situation
that requires subnetting, let's do it."
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So in this opening IP subnetting
nugget, I'm going to show you how
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to subnet based on network requirements.
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So here's the situation.
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Here is something that would
require custom subnetting.
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This organization has purchased
the Class C address 216.21.5.0.
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Now, [inaudible] stop right there.
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What do you mean purchase?
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Why do I need to buy IP addresses?
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Well, keep in mind than when we're working with
IP addresses, there are private IP addresses
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and there are public IP addresses.
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The private one, you don't have to pay for,
they are available to you, you can create them,
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make them up whatever you want
inside of your own network,
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I believe we've talked about them already.
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They are anything that starts with a number 10,
they're anything with 172.16 through 31.255.255
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if you will slash 16, or they are
192.168 dot anything slash 16.
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So essentially if the first two octets are
this, this, or the first octet is that,
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it is a private address as in, they're yours.
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You can create them, make them up, design
your own internal networks all day,
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but those IP addresses don't
work on the internet,
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they are blocked by every single
service provider that are out there.
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So, public addresses are anything that is
a valid address outside of those ranges.
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For example, this one.
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So, this organization has purchased a
block of public addresses that they want
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to use inside of the organization.
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They want all of the devices inside of their
organization to be directly on the internet
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without the use of NAT or
any technology like that.
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Now, is that normal?
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I've seen it before, but
it's not a normal thing,
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but it works really well
for a subnetting scenario.
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So that's the situation that
we've found our self in.
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So the organization has purchased a
Class C address that is this block.
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So that means they can't go outside of that.
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Now, when you purchase a Class C address,
216.21.5.0 with a Class C subnet mask,
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255.255.255.0, how many networks do you get?
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One, right, 216.21.5.
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How many hosts do you get?
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Well, 256 IP addresses total here, 254
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that are usable 'cause you can't
use 0 and you can't use 255.
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So everything in that squishy [inaudible]
center is usable on the host side.
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But, here's the problem, let's look
at this situation 'cause it says,
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the organization has purchased this and
we'd like to use it to address this network.
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So we'll look at this.
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Now, let me ask you the question, how
many networks do you see in this picture?
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Pause the nugget, think about it.
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I see five, 1, 2, 3, 4, 5.
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Essentially, every interface
of a router represents the end
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of a network and the beginning of a new.
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So, if I connect another interface here to
another group of computers, that would be six,
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you know, there would be another network that
would be represented there in that picture.
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So, every interface of a router divides
up a network and think about it,
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that's what a router's life blood is.
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It's to divide networks to stop broadcast
like a broadcast that happens here
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on this network stays on
this network because it's--
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that's all, you know, internal right there.
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The router will not let that
pass, you shall not pass.
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So, we look at this and we go, "Okay,
well this is-- this poses a problem."
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We have our organization which
has five networks, right?
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But, we've purchased a Class C address
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that only gives us one network,
216.21.5, inter-subnetting.
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Subnetting or the full word, subnetworking,
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is taking your one network
and dividing it up into many.
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Now, if I were to break it
down even further, I would say,
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it's sacrificing how many hosts you can
have per network to get more networks.
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00:05:01,566 --> 00:05:08,316
So, essentially, we move this bar over a little
bit more so that, you know, maybe half of that 0
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if you will represents the network side
and half of it represents the host.
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00:05:13,126 --> 00:05:15,716
Now, looking at it in a decimal
sense, it's crazy,
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you can't just draw a line
through a 0 like that.
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00:05:17,876 --> 00:05:22,086
But when you break it out in binary and you
go, "Oh, well, there's actually 8 bits,"
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00:05:22,306 --> 00:05:26,216
and actually, they're all 0s
and that-- that's really 8.
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There's 8 bits that represent that 0.
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We could move the line over and maybe,
you know, you could put a line in there,
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somewhere that divide, you know, these 3 bits go
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to the network side, these
3 bits go to the host.
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That's what subnetting here is.
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So here's the process, three
steps every single time.
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One, determine the number of networks
that you need and convert it to binary.
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Two, reserve the bits in the subnet
mask and find your increment.
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And three, use the increment
to find your network ranges.
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00:05:57,486 --> 00:06:00,756
Now, at this point, those three steps don't mean
anything 'cause we haven't gone through them,
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00:06:00,756 --> 00:06:02,406
so let's start treading some water.
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00:06:02,916 --> 00:06:08,216
This was the network that we were given,
216.21.5.0, that's what we purchased
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from our internet service provider that we're
going to subnet for our whole organization.
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00:06:12,046 --> 00:06:15,916
So step one is to determine the number
of networks and convert it to binary.
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Well, that's an easy step.
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00:06:17,686 --> 00:06:21,616
We determined on the last slide that
there are going be five total networks.
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Remember all every single one of those
router interfaces represented a network
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that they were connected to.
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00:06:26,526 --> 00:06:31,436
So, five networks and we need to convert it
to binary number into our [inaudible] skills
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00:06:31,436 --> 00:06:40,466
from the last nugget, 128, 64, 32, 16, 8, 4,
2, 1 is our values that we're going to use
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for subnetting are binary value, so
no, no, no, no, no, yes, no, yes.
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So five really represents 00000101 in the binary
realm, that's it, that's the whole first step.
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So, second step; reserve bits in the
subnet mask and find your increment.
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Well, what does that mean?
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00:07:05,096 --> 00:07:09,536
Well, the way that we do this is
to take that subnet mask and look
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at it the way our network
devices look at it in binary.
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So, now, you're going to want to shortcut this
at the beginning, don't do it at the beginning.
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I'll show you some shortcuts later, but
while you're first starting in this,
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you want to write that subnet
mask in all binary.
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It's not as hard as it sounds,
right, 255.255.255.0.
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What is that is a binary number.
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What is 255?
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All 8s or with all 8s [laughs],
I'm totally wrong.
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No, all 1s, it's eight 1s, one, two, three,
four, five, six, seven, eight dot one two,
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three, four, five, six, seven, eight dot one
two, three, four, five, six, seven, eight dot.
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So, I'm just converting that whole thing
to binary and then what's 0 in all binary?
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Real easy, right?
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0000000, so that is what it
looks like in all binary, okay.
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So what does it mean to reserve
bits in the subnet mask?
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Okay, well, we have to look at this.
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We say, determine the number of networks.
128
00:08:04,876 --> 00:08:07,616
Now, I'm looking right here, okay five networks.
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How, now, let me ask you a question.
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This is a little tricky the
first time you hear it.
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How many bits did it take to get the number 5?
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Three, 3 bits, that's really common.
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You probably-- some of you probably
did this, to look at this and say, "Oh,
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well 2 bits 'cause I only see two 1s.
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Well, you're thinking about it little of.
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If you're thinking 2 bits, that's
what it would mean, just those 2 bits.
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What's the biggest number
you could get with 2 bits?
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Three, right, 1 plus 2 would be 3.
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So we'll look at this and we go,
"Okay, well, it's actually 3 bits.
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I can't get the number 5 with
any less than 3 bits, right?
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So now, I need you to take
another mental leap with me.
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Previously, in all-- everything
that we've talking about,
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we've said 255 represents the
network, 0 represents the host, right,
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when we're lining up the
subnet mask to the IP address,
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that's how we find our network and host.
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00:09:00,646 --> 00:09:02,856
So, so I need you to take a mental jump with me.
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Is it okay to make the statement, 1s represents
the network and 0s represent the host?
148
00:09:10,346 --> 00:09:11,636
So, is that an okay statement?
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Yes, okay, okay good.
150
00:09:13,096 --> 00:09:15,906
So we've got, 1s represent the network.
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00:09:15,906 --> 00:09:20,666
Okay, let's start putting some of these
pieces together so I can't get the number 5,
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I can't and let me put a little more to this.
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It's like I'm unpacking this as we go.
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00:09:25,056 --> 00:09:30,076
So I can't get the number 5 with any less than
3 bits and I've just made the statement that,
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that network bits really are 1s, so what does it
mean when I say reserve bits in the subnet mask?
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Here's what it means.
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It means, I pick up right where the 1s
leave off and I say, I need one, two,
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three network bits, the rest
of this can stay host.
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00:09:46,796 --> 00:09:49,686
I can't get five networks
with any less than 3 bits,
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00:09:49,686 --> 00:09:52,556
so I'm going to add 3 more
network bits onto there.
161
00:09:52,556 --> 00:09:56,216
Now, whoa, stop the train,
big statement right there.
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Wait a second, wait a second,
wait a second Jeremy.
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I thought this was 101, why
did you put 1, 1, 1 there?
164
00:10:04,126 --> 00:10:10,186
Well, it doesn't really matter at all
what the binary number is up here, at all.
165
00:10:10,256 --> 00:10:15,186
What we're after is how many bits does
it take to get that binary number?
166
00:10:15,426 --> 00:10:20,406
If I had the number 20, I would look up
here and I go, "Okay, well 20 is 00010100.
167
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I don't really care if that is 101.
168
00:10:23,246 --> 00:10:26,476
I just know that it takes 5
bits to get the number 20.
169
00:10:26,536 --> 00:10:27,476
That's what I'm after.
170
00:10:27,476 --> 00:10:30,796
I'm not really after the binary number
at all, I'm just after how many bits.
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So, when I come down here, I can say, "Okay,
well, as I'm looking at my subnet mask,
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I need five networks so I need
to extend to that subnet mask
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00:10:38,696 --> 00:10:42,006
by 3-network bits to make that possible."
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00:10:42,566 --> 00:10:47,016
Okay, so believe it or not, at this point,
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we already know what are subnet mask
is going to be for this entire network.
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00:10:51,806 --> 00:10:57,096
How? Well, we can take this and convert it back
to a decimal number, pretty straightforward,
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255.255.255 because, these first
three haven't change and frankly,
178
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they can't change because
that's what we're given.
179
00:11:06,346 --> 00:11:09,536
We can only subnet the host bits
'cause that's our playground.
180
00:11:09,536 --> 00:11:12,306
The 0s are where we can kind
of make modifications.
181
00:11:12,466 --> 00:11:14,106
This is what the service provider gave us.
182
00:11:14,106 --> 00:11:16,356
That's what we bought so we can't change that.
183
00:11:16,356 --> 00:11:18,576
So, what is this last one?
184
00:11:18,666 --> 00:11:22,476
Well, that's where we have to
use our binary to decimal skills.
185
00:11:22,476 --> 00:11:26,006
I have to take this and convert
it back to a decimal number.
186
00:11:26,186 --> 00:11:30,036
So let's line it up, one, two,
three, one, two, three, four, five.
187
00:11:30,396 --> 00:11:38,736
So I really have to take 128 plus 64 plus
32, carry the 1 minus 2, 224 [laughs], yeah,
188
00:11:38,736 --> 00:11:42,176
trust me, you'll start getting
used to some of the common values.
189
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They're going to say, it's the beauty of
something and there's only eight numbers
190
00:11:45,506 --> 00:11:47,766
that you're really going to run into.
191
00:11:47,766 --> 00:11:53,996
So, our new subnet mask becomes 255.255.255.224.
192
00:11:53,996 --> 00:11:56,036
Every router will have that.
193
00:11:56,036 --> 00:11:59,016
Every computer will have that
subnet mask in that network
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00:11:59,016 --> 00:12:00,626
that we just saw on the slide, that picture.
195
00:12:00,796 --> 00:12:04,676
Everything will use that subnet mask and
you can be like, "Yeah, doing the dance,
196
00:12:04,676 --> 00:12:07,546
I got this subnet mask we're going
to use for the whole network."
197
00:12:07,806 --> 00:12:10,996
That's great, but it doesn't
mean a thing to us yet.
198
00:12:10,996 --> 00:12:11,946
It's just a number.
199
00:12:11,946 --> 00:12:17,036
It's like, "Well, there it is, that's the
right answer, choose C, you know, if you will,
200
00:12:17,036 --> 00:12:18,496
but I don't know what that means yet."
201
00:12:19,006 --> 00:12:21,226
Well that's the second half of this.
202
00:12:21,226 --> 00:12:24,296
We reserve the bits in the subnet
mask and find your increment.
203
00:12:25,076 --> 00:12:26,686
What is the increment?
204
00:12:26,686 --> 00:12:27,846
So we did the reservations.
205
00:12:27,846 --> 00:12:35,936
So, the increment is actually the lowest
network bit converted back to a decimal number.
206
00:12:36,956 --> 00:12:37,976
So, let's think about it.
207
00:12:37,976 --> 00:12:42,266
This 128, 64, 32.
208
00:12:43,576 --> 00:12:47,716
The lowest network bit is essentially
where the 1s end and the 0s begin.
209
00:12:47,716 --> 00:12:52,186
The lowest network bit converted back to
a decimal number represents our increment.
210
00:12:52,776 --> 00:12:57,456
Okay. So, [laughs] still another one
of those right answer things like,
211
00:12:57,456 --> 00:13:01,336
"I got the subnet mask, I got the
increment, I have no idea what it means yet."
212
00:13:01,636 --> 00:13:07,656
Well the last step is to use that
increment to find your network ranges.
213
00:13:07,656 --> 00:13:14,266
Okay, this is where it all gets-- put together,
32 is our increment, this is what we were given
214
00:13:14,266 --> 00:13:19,836
and we can start using that increment to find
out how many IP addresses I get per network?
215
00:13:20,486 --> 00:13:27,586
The way I do that is simple math,
216.21.5.0 is where I start.
216
00:13:27,866 --> 00:13:32,306
And then I just start adding that increment
in whatever octet, whatever position.
217
00:13:32,306 --> 00:13:39,336
Let's look at it, it's in the fourth octet
so I go, okay, next one is 216.21.5.1.32.
218
00:13:39,696 --> 00:13:41,056
0 plus 32 is 32.
219
00:13:41,056 --> 00:13:49,836
216.21.5.64.96.128, I'm just
adding 32 dot, dot, dot, you know,
220
00:13:49,836 --> 00:13:54,116
I just keep going down all the way, you
know, filling those in and you can keep
221
00:13:54,116 --> 00:13:55,496
that going down all the way as well.
222
00:13:55,906 --> 00:13:56,706
What is that?
223
00:13:57,176 --> 00:14:01,086
That is the starting position for each network.
224
00:14:01,086 --> 00:14:09,516
216.21.5.0 is where network one begins
and it goes through, you know, now,
225
00:14:09,516 --> 00:14:13,706
we can go back once we just go down, we can
go back and fill in the last IP address.
226
00:14:13,706 --> 00:14:19,446
216.21.5 dot-- what's 1 less than 32?
227
00:14:20,616 --> 00:14:24,236
I know some of you are like,
"Is it really that simple?"
228
00:14:24,346 --> 00:14:26,426
Yeah and it's not tricky, 31 right?
229
00:14:26,426 --> 00:14:35,046
216.21.5.63 that's the last IP address before 6,
so I'm filling in the last one just by looking
230
00:14:35,046 --> 00:14:38,316
at where the next one starts and I go,
"Okay, minus 1 and that must be that."
231
00:14:38,316 --> 00:14:38,786
That fills in.
232
00:14:38,786 --> 00:14:44,946
So, this goes to 216.21.5.95 and dot,
dot, dot, dot, dot, dot, dot, you know,
233
00:14:45,036 --> 00:14:46,816
this-- we'll just keep subtracting 1.
234
00:14:47,276 --> 00:14:49,296
But now, it's become real.
235
00:14:49,746 --> 00:14:50,386
Let me show you.
236
00:14:50,386 --> 00:14:56,456
I come back here to my network situation
and I realized I needed five networks.
237
00:14:56,456 --> 00:14:57,786
So now, I can start assigning them.
238
00:14:57,786 --> 00:15:05,006
This is actually going to be
216, no, network one 216.21.5.0.
239
00:15:05,006 --> 00:15:13,136
through 31 with the 255.255.255.224 subnet
mask, I won't write that every time,
240
00:15:13,136 --> 00:15:15,956
but here's the subnet mask, here's the range.
241
00:15:15,956 --> 00:15:23,006
So I will assign the devices in that network
IP addresses in this range, 0 through 31.
242
00:15:23,576 --> 00:15:28,756
So, you know, I would probably
assign the router, the first one.
243
00:15:28,756 --> 00:15:35,766
So the router would get 216.21.5.1 and then, you
know, maybe a DHCP scope for the rest of them,
244
00:15:35,766 --> 00:15:41,366
you know, maybe this computer is .2 and the
next computer is .3 and all that kind of stuff.
245
00:15:41,366 --> 00:15:43,526
That's-- they're actually go,
"As long as I don't exceed 31."
246
00:15:43,526 --> 00:15:47,086
Now keep in mind, whoa, whoa, whoa wait
a second [inaudible] stop the train.
247
00:15:47,906 --> 00:15:55,056
Remember, when we're doing IP networking, we can
never use the first address or the last address.
248
00:15:55,356 --> 00:15:59,676
Why? The first one represents the network
and the last one represents the broadcast.
249
00:15:59,676 --> 00:16:05,296
So, I can't actually assign something 216.21.5.0
because that identifies the whole network.
250
00:16:05,296 --> 00:16:07,016
It's an identifier, it's not valid.
251
00:16:07,146 --> 00:16:12,716
Same thing, I can't assign someone
216.21.5.31 because that's a broadcast.
252
00:16:12,716 --> 00:16:17,646
If I wanted to send a message to everybody on
that network, I would send it to that IP address
253
00:16:17,646 --> 00:16:19,606
to .31 and everybody would get it.
254
00:16:19,606 --> 00:16:21,446
That's a-- it's a broadcast address.
255
00:16:21,446 --> 00:16:22,156
So we can't assign it.
256
00:16:22,156 --> 00:16:26,866
So usable, we actually get
1 through 30 for that range.
257
00:16:28,026 --> 00:16:30,836
So that's network one, you know,
so that's number one right there.
258
00:16:31,056 --> 00:16:36,646
Number two, is this guy, 216.21.5.32 through 63.
259
00:16:37,346 --> 00:16:45,066
So, you'd come back here and say, "Okay, you
are 216.21.5.32 through, what did I say 63,
260
00:16:45,446 --> 00:16:50,346
63 but knowing realizing I can't
give 32 or 63 to an actual device,
261
00:16:50,346 --> 00:16:52,516
so 'cause that's the network,
that's the broadcast.
262
00:16:52,516 --> 00:16:59,886
So usable actually get 33 through 62
so maybe the router gets 216.21.5.33.
263
00:16:59,886 --> 00:17:01,246
That's everybody's default gateway.
264
00:17:01,246 --> 00:17:04,806
That's how they get off of their
network is going to that 33 address.
265
00:17:04,806 --> 00:17:10,196
And then this guy maybe is .34 and his friend
is .35, you know, and all the other devices
266
00:17:10,196 --> 00:17:13,096
that are on that network, get IP
addresses that are in there as long
267
00:17:13,096 --> 00:17:15,096
as I don't assign something to that.
268
00:17:15,096 --> 00:17:18,546
So, what I've done, take a moment [inaudible].
269
00:17:18,766 --> 00:17:20,066
Let's look at the concept.
270
00:17:20,066 --> 00:17:24,836
I've taken the one network and broken
it down to where I can address all
271
00:17:24,836 --> 00:17:26,316
of the networks in this situation.
272
00:17:26,316 --> 00:17:27,966
Now, let's fill in some questions.
273
00:17:28,756 --> 00:17:33,096
Now, some of you mathematicians out there
are looking and going, "Wait a second,
274
00:17:33,096 --> 00:17:34,576
this is going to give me more than five."
275
00:17:34,576 --> 00:17:39,426
I can see that, it's one, two, three, four,
five and then I mean, this goes higher, right?.
276
00:17:39,596 --> 00:17:44,876
It does, it's going to give you more than
five because of how the binary works out.
277
00:17:44,986 --> 00:17:48,326
Let's-- that's just, you know, if you
look at it, you only have eight numbers
278
00:17:48,326 --> 00:17:51,636
that it could be, so it's going
be something in that range.
279
00:17:51,636 --> 00:17:54,446
So you're-- the way to think of
it is this scheme will give you
280
00:17:54,446 --> 00:17:58,546
at least the five networks
that you asked for, okay?
281
00:17:59,096 --> 00:18:03,516
So, next question then becomes well, "How
do I know, how many networks it'll give me?
282
00:18:03,516 --> 00:18:08,226
Or, for that matter, "How do I know how many
hosts I can actually have on the network?"
283
00:18:09,426 --> 00:18:10,786
Well, there's a simple formula.
284
00:18:10,936 --> 00:18:17,596
I say simple if you have a calculator, but
simple to where you can type in 2 to the power
285
00:18:17,596 --> 00:18:23,256
of how ever many bits you would like to
put in there and find that question out.
286
00:18:23,256 --> 00:18:25,046
So, let's do it this way.
287
00:18:25,286 --> 00:18:28,766
Let's say, you're asking the question,
"Well, how many networks does this give me?"
288
00:18:29,316 --> 00:18:34,386
Well, the way you can find it out is to look
at how many subnet bits you ended up adding.
289
00:18:34,526 --> 00:18:40,146
So, 2 to the power of 3 in this case
because I added three subnet bits.
290
00:18:40,556 --> 00:18:44,286
So 2 to the power of 3 will tell
you how many networks you get.
291
00:18:44,286 --> 00:18:51,836
Now, 2 to the power of 3, it's a little
simple 'cause you go "Okay, 2 times 2 is 4
292
00:18:52,106 --> 00:18:56,796
and then 2 times, you know, essentially
2 times 2 times 2 is 8, you know.
293
00:18:56,796 --> 00:19:00,056
If you're doing it in your head, it's
like, "Okay, I can do that kind of math,"
294
00:19:00,056 --> 00:19:03,436
but when you get into the larger
numbers, it gets really tough,
295
00:19:03,436 --> 00:19:05,086
so what if you don't have a calculator.
296
00:19:05,086 --> 00:19:09,016
So, that's why I showed in the last
nugget, these are all the powers of 2.
297
00:19:09,156 --> 00:19:12,936
So 2 to the power of 0 is
1, to the power of 1 is 2,
298
00:19:12,936 --> 00:19:15,776
to the power of 2 is 4, to the power of 3 is 8.
299
00:19:15,776 --> 00:19:19,336
As long as you remember that it counts
from 0, you should be fine, just go, "Okay,
300
00:19:19,336 --> 00:19:21,356
well the 2 to the power of 3
is right here, so that's 8."
301
00:19:21,356 --> 00:19:24,726
So you can do that and so that way, when you
get to this larger number, you don't have to sit
302
00:19:24,726 --> 00:19:28,156
with a piece of paper going 2 times 2 times
2, you can just look right here and go, "Okay,
303
00:19:28,156 --> 00:19:30,196
2 to the power of 7 is actually 128."
304
00:19:30,196 --> 00:19:30,876
See what I mean.
305
00:19:30,876 --> 00:19:36,186
So 2 to the power of 3 tells you with this
scheme, if I work this all the way down,
306
00:19:36,186 --> 00:19:41,916
I will have a total of eight
networks or eight subnetworks,
307
00:19:41,916 --> 00:19:44,786
subnets that I created with this scheme.
308
00:19:44,786 --> 00:19:48,446
Or, if I want to say, "Well, how
many host do I get per network?"
309
00:19:48,826 --> 00:19:54,536
Well, same formula, 2 to the power of, in this
case, we're looking at host bits that's one,
310
00:19:54,536 --> 00:19:59,506
two, three, four, five, five,
there's five 0s left over equals,
311
00:19:59,506 --> 00:20:02,026
you know, looking up here, is 32.
312
00:20:02,026 --> 00:20:02,116
right?
313
00:20:03,736 --> 00:20:09,146
But you have to remember, whenever you're
doing the number of host, to always subtract 2.
314
00:20:09,576 --> 00:20:10,436
What do you think that is?
315
00:20:11,756 --> 00:20:12,336
You remember, right?
316
00:20:12,336 --> 00:20:15,216
Can't use the first one, can't use
the last one so those don't count.
317
00:20:15,426 --> 00:20:24,436
So, we'll say usable host end up
being 30 hosts per network, right?
318
00:20:25,886 --> 00:20:29,326
You have just done your first
subnetting question.
319
00:20:29,976 --> 00:20:36,536
Now, [laughs] this is, you know, you grab the
child and you throw him in the water, right,
320
00:20:36,536 --> 00:20:39,576
they're going, [inaudible], you
know, water splashing everywhere.
321
00:20:39,576 --> 00:20:44,056
That's the kind of feeling that I have
right now as you're going, "Whoa," you know.
322
00:20:44,056 --> 00:20:47,256
It's kind of like I caught a little
piece, I'm treading in a little water
323
00:20:47,256 --> 00:20:49,516
and little bits here and there, but oh, man!
324
00:20:49,516 --> 00:20:50,846
So let's do another one.
325
00:20:51,346 --> 00:20:55,176
For this one, I'm going to skip the picture
'cause it just gets too big to draw.
326
00:20:55,716 --> 00:21:00,846
But in this scenario, we've got
a Class C network, 195.5.20.0
327
00:21:01,096 --> 00:21:03,836
and we want to break that into 50 networks.
328
00:21:04,016 --> 00:21:06,116
Okay, now, and let's get some bearing here.
329
00:21:06,646 --> 00:21:13,796
That means that we've got one network,
195.5.20.0 with a Class C subnet mask,
330
00:21:13,796 --> 00:21:19,026
255.255.255.0 and we want
to take this one network,
331
00:21:19,136 --> 00:21:23,456
'cause this typically gives us
one network which is 195.520,
332
00:21:23,456 --> 00:21:26,556
and break it into 50 different subnetworks.
333
00:21:26,556 --> 00:21:27,786
[laughs] It's a question.
334
00:21:27,936 --> 00:21:28,916
Is that even possible?
335
00:21:28,916 --> 00:21:29,666
Can we do that?
336
00:21:30,016 --> 00:21:30,946
Well, let's try it.
337
00:21:31,126 --> 00:21:36,906
So first of, step number one, is to determine
the number of networks and convert to binary.
338
00:21:36,906 --> 00:21:40,186
So we need 50 subnets, all right.
339
00:21:40,446 --> 00:21:47,096
Get a our old standby binary chart
up here, 128, 64, 32, 16, 8, 4, 2, 1.
340
00:21:47,896 --> 00:21:56,016
So 50 as a binary number, so I'm going to
go 0, 0, 1, try that, oh, let me finish this
341
00:21:56,016 --> 00:21:59,566
and then I'll give you my shortcut, 50 minus 32?
342
00:22:00,036 --> 00:22:03,636
That will be 5, 4, 8, 1, 18 left, all right?
343
00:22:03,636 --> 00:22:08,466
1, that would be 16, they'll
be 2 left, so 0, 0, 2, 0.
344
00:22:08,736 --> 00:22:14,146
[laughs] [inaudible], 0, 0, 1, on the
2 is 0, and there's a binary number.
345
00:22:14,416 --> 00:22:20,026
So, 00110010, okay.
346
00:22:20,476 --> 00:22:21,886
Step one, check.
347
00:22:21,886 --> 00:22:22,286
We got it.
348
00:22:22,786 --> 00:22:25,966
Now, step two, reserve bits in the
subnet mask and find your increment.
349
00:22:25,966 --> 00:22:27,866
Again, don't skip it at this point.
350
00:22:27,866 --> 00:22:32,716
It's going to take a little bit of time but
we're going to write the Class C subnet mask
351
00:22:32,716 --> 00:22:38,876
in there and all binary, one, two, three, four,
five, six, seven, eight, one, two, three, four,
352
00:22:38,876 --> 00:22:44,076
five, six, seven, eight, one, two, three,
four, five, six, seven, eight, okay.
353
00:22:44,076 --> 00:22:46,446
So, here's what I want to
show you a little shortcut.
354
00:22:46,596 --> 00:22:51,386
So the statement is reserve bits in the
subnet mask and find your increment.
355
00:22:51,386 --> 00:22:55,546
So, we have to ask the question, how many
bits did it take to get the number 50?
356
00:22:56,326 --> 00:22:58,696
And I would submit to you, 6 bits
357
00:23:00,106 --> 00:23:03,656
because I can't get the number 50
with any less than 6 bits, okay.
358
00:23:03,996 --> 00:23:07,096
Into your shortcut number one here,
one of the things we're always trying
359
00:23:07,096 --> 00:23:10,396
to do is do things a little bit
faster especially when we're talking
360
00:23:10,396 --> 00:23:13,486
about certification exams and time is on
the line and all that, you want to try
361
00:23:13,486 --> 00:23:14,906
and do things as fast as possible.
362
00:23:15,176 --> 00:23:18,956
When you're finding the binary number right here
where it says, determine the number of networks
363
00:23:18,956 --> 00:23:22,586
and convert to binary [inaudible],
when you're finding that binary number,
364
00:23:22,946 --> 00:23:26,026
as soon as you put the first
one on the drawing board,
365
00:23:26,376 --> 00:23:29,096
do you know how many bits it's
going to take to get that number?
366
00:23:30,846 --> 00:23:31,656
Yeah, right?
367
00:23:31,786 --> 00:23:37,336
So, as soon as I know my first one goes at
the 32, I don't have to spend time figuring
368
00:23:37,336 --> 00:23:41,096
out the rest of this because I know,
no matter what the rest of this is,
369
00:23:41,346 --> 00:23:43,186
I don't really care what the rest of this is.
370
00:23:43,186 --> 00:23:47,646
I just care that it takes 6
bits to get 50 networks, right?
371
00:23:47,816 --> 00:23:50,266
So, that can save you a little
bit of time there.
372
00:23:50,266 --> 00:23:54,776
Okay. So now, we're going to do step two
which is reserve the bits in the subnet mask.
373
00:23:54,776 --> 00:23:59,946
Now, are we after-- here's my question-- next
question for you, are we after 50 networks
374
00:24:00,696 --> 00:24:04,076
or are we after 50 hosts on our networks?
375
00:24:04,596 --> 00:24:06,296
Well, the answer is 50 networks.
376
00:24:06,296 --> 00:24:09,306
You're like, you know, "We'll, Jeremy, that's
what the question says, 50 networks, right?"
377
00:24:09,436 --> 00:24:14,116
Well, yes, and I'm going to keep asking you this
question and the reason why is because later
378
00:24:14,116 --> 00:24:17,036
on in the next nugget, we're going
to change that question a little bit
379
00:24:17,656 --> 00:24:19,996
to the host per network,
but for now, 50 networks.
380
00:24:19,996 --> 00:24:25,646
So, I go, "Okay, I need-- that means
then, I need 6 network bits, right?"
381
00:24:25,646 --> 00:24:32,326
And we know that 1s are network bits, so I'm
going to go one, two, three, four, five, six,
382
00:24:32,326 --> 00:24:35,156
it does-- again, it doesn't matter
what these were at, it doesn't matter,
383
00:24:35,156 --> 00:24:38,446
I need 6 network bits 'cause
I can't get 50 networks,
384
00:24:38,446 --> 00:24:40,906
I can't get 50 subnets with
any less than 6 bits.
385
00:24:40,906 --> 00:24:44,826
Okay, 0, 0 is left over, not
much for the host, right?
386
00:24:45,126 --> 00:24:48,406
So, that gives us what our new subnet mask is.
387
00:24:49,186 --> 00:24:51,016
In decimal form, we know the subnet mask
388
00:24:51,016 --> 00:24:59,056
for the network will be 255.255.255.,
now what is this in decimal?
389
00:24:59,486 --> 00:25:02,066
Well, two approaches you could take.
390
00:25:02,256 --> 00:25:08,796
You could add 128, 64, 32,
16, 8, 4 all together, right?
391
00:25:08,796 --> 00:25:13,106
And you could that number or if these are
all 1, we know that they're 255, right?
392
00:25:13,486 --> 00:25:17,486
So, in this case, it will be a lot easier
just to figure out what we don't have.
393
00:25:17,486 --> 00:25:20,706
We don't have a 2 and we don't have a 1, right?
394
00:25:20,706 --> 00:25:23,696
So, we could either add all these
numbers up and get the answer
395
00:25:23,696 --> 00:25:29,786
or we could take 255 minus 3 which gives us 252.
396
00:25:29,786 --> 00:25:32,356
Forgive me, I'm starting to throw a
little shortcuts in here as we go,
397
00:25:32,356 --> 00:25:37,406
just go a little faster, 252, but
if the shortcuts don't work for you,
398
00:25:37,406 --> 00:25:39,116
you know, add them up, definitely.
399
00:25:39,116 --> 00:25:41,016
It's much better to take
a little more time adding
400
00:25:41,016 --> 00:25:43,096
and get the right answer than
go, "How was that again?"
401
00:25:43,096 --> 00:25:45,676
So, 252 is our subnet mask.
402
00:25:45,676 --> 00:25:47,646
Now, let me add yet another piece.
403
00:25:47,646 --> 00:25:52,186
I add these little pieces as we go
through this to enhance what you know.
404
00:25:52,846 --> 00:25:55,836
Now, we've been talking all along,
you know, we've been saying--
405
00:25:55,836 --> 00:25:57,486
I think I'd showed you in an earlier nuggets
406
00:25:57,486 --> 00:26:05,446
like a slash 24 really equals
255.255.255.0, right?
407
00:26:05,446 --> 00:26:10,646
That's kind of a shorthand, that's called
CIDR notation and all that and I said
408
00:26:10,646 --> 00:26:21,176
like slash 8 equals 255.0.0.0,
all those kinds of things.
409
00:26:21,176 --> 00:26:23,116
Now, we can actually see why?
410
00:26:23,116 --> 00:26:28,236
This CIDR notation is really just
the number of 1s in the subnet mask.
411
00:26:28,236 --> 00:26:43,956
So, when I look at a Class C subnet mask, I can
say, "Well, that's 255.255.255.0" or I can say,
412
00:26:43,986 --> 00:26:46,116
"Well, that's eight 1s, eight 1s, eight 1s,
413
00:26:46,116 --> 00:26:52,976
so that 24 1s thus slash 24 is
a shortcut way of writing that.
414
00:26:52,976 --> 00:26:55,526
You see why it's kind of cool?
415
00:26:55,526 --> 00:26:59,216
Once you know the binary, you're like,
"Oh, that's where they get that from."
416
00:26:59,216 --> 00:27:05,486
So, you know, a Class A address only has
8 bits in that so it becomes a slash 8.
417
00:27:07,236 --> 00:27:12,746
So, the reason I say that is I want to
start writing this, you know, this is--
418
00:27:12,746 --> 00:27:19,896
we started with a slash 24 here but I
want to start writing this in both decimal
419
00:27:20,046 --> 00:27:23,886
and CIDR notation because you're
going to see examples of both
420
00:27:23,886 --> 00:27:25,916
in the real world and on the exam.
421
00:27:25,916 --> 00:27:38,596
This, 255.255.255.252, is actually the original
24 bits plus 6 more that I added there, right?
422
00:27:38,596 --> 00:27:39,826
That'll be a slash 30.
423
00:27:39,896 --> 00:27:43,736
That would be representative
of that subnet mask.
424
00:27:44,436 --> 00:27:49,376
So, again, we're just talking about
ways of writing the subnet mask.
425
00:27:49,376 --> 00:27:54,396
I can write it this way or
I can write it that way.
426
00:27:54,616 --> 00:27:56,576
They both mean the same thing.
427
00:27:56,576 --> 00:27:58,726
So, okay, let's catch back up where we were.
428
00:27:58,726 --> 00:28:02,796
We determined we needed 50 networks,
that's what the question gave us.
429
00:28:02,796 --> 00:28:06,426
We determined it was 6 bits,
so we reserved our 6 bits,
430
00:28:06,426 --> 00:28:13,486
so now we know what our subnet mask
is going to be for this whole network.
431
00:28:13,486 --> 00:28:15,346
So now, we need to find our increment.
432
00:28:15,496 --> 00:28:19,786
So, I'm going to come in here and
let me say, "The lowest network bit,
433
00:28:19,786 --> 00:28:23,556
the last network bit converted back to
a decimal number is a 4, [inaudible]."
434
00:28:23,556 --> 00:28:24,876
That is my increment.
435
00:28:24,876 --> 00:28:29,746
So I can come in here and say, "I'm going to
use that increment to find my network ranges,
436
00:28:29,746 --> 00:28:39,576
195.5.20.0 and just start adding 4 to the last
octet 'cause that's where the increment is."
437
00:28:39,676 --> 00:28:49,396
So, 195.5.20.4, .20, just go on faster, .20.12,
.20-- you see where this is going, .16 dot, dot,
438
00:28:49,396 --> 00:28:52,606
dot, dot, dot, dot, down, down and down we go.
439
00:28:52,606 --> 00:28:58,976
So that's the start of every single network
that I would need for this organization.
440
00:28:58,976 --> 00:28:59,896
So what's the end?
441
00:28:59,896 --> 00:29:08,026
Well, just subtract 1, 3,
subtract 1, 7, subtract 1, 11.
442
00:29:08,626 --> 00:29:12,506
So this-- these are actually go--
now, I'm writing the shorthand.
443
00:29:12,606 --> 00:29:21,656
It's actually 195.5.20.0 through 195.5.20.3
through, you know, you see what I mean?
444
00:29:21,656 --> 00:29:22,676
So I'm just writing them shorthand.
445
00:29:22,676 --> 00:29:26,956
Now, keep in mind, we know that
we cannot use the last IP address
446
00:29:26,986 --> 00:29:28,186
or the first IP address, so what is our usable?
447
00:29:28,216 --> 00:29:28,516
1 through 2.
448
00:29:28,546 --> 00:29:29,056
What is our usable?
449
00:29:29,086 --> 00:29:29,446
5 through 6.
450
00:29:29,476 --> 00:29:31,336
We actually have two, count them,
one, two usable hosts for our network.
451
00:29:31,366 --> 00:29:33,286
And if you think about it, if we're
taking a Class C and breaking in into
452
00:29:33,316 --> 00:29:34,966
at least 50 subnets, well, good
grief, we have to give somewhere.
453
00:29:34,996 --> 00:29:37,096
Now, you might be saying and scratching your
head going, "Okay, this is just getting absurd.
454
00:29:37,126 --> 00:29:38,926
Where would we use a subnet mask
that only has two hosts per network?"
455
00:29:38,956 --> 00:29:39,526
Well believe it or not.
456
00:29:39,556 --> 00:29:41,596
You just found the second most subnet--
most coomon subnet mask in the world.
457
00:29:41,626 --> 00:29:42,976
The most common subnet mask is a slash 24.
458
00:29:43,006 --> 00:29:44,956
The second most common subnet mask
is a slash 30 because it's used all
459
00:29:44,986 --> 00:29:45,946
over the place when you have WAN links.
460
00:29:45,976 --> 00:29:46,636
Oh man, what a perfect fit.
461
00:29:46,666 --> 00:29:48,316
So, if you have router one connected
to a network up here, you know,
462
00:29:48,346 --> 00:29:49,606
that you got your computer's
humming along up there.
463
00:29:49,636 --> 00:29:50,806
Router two is connected to a network down here.
464
00:29:50,836 --> 00:29:52,576
And then you've got a WAN link
in the middle managed by AT&T
465
00:29:52,606 --> 00:29:54,706
or whatever service provider you're using to
connect, that we'll say, the Arizona office
466
00:29:54,736 --> 00:29:55,906
to the Texas office, to connect these two sites.
467
00:29:55,936 --> 00:29:57,976
Well, this is a network and I don't want
to waste IP addresses on that network
468
00:29:58,006 --> 00:29:58,906
because I know I'll only have how many?
469
00:29:58,936 --> 00:29:59,656
Two devices on that network.
470
00:29:59,686 --> 00:30:00,976
One here on this side, that's
our router, and one here.
471
00:30:01,046 --> 00:30:04,806
This is such a custom fit for this kind of
environment because I can say, "Okay, well,
472
00:30:05,106 --> 00:30:12,146
this will be the 192.5.20.0
network slash 37 netmask.
473
00:30:12,316 --> 00:30:17,266
So, you will actually be .1 and you
will be .2, the two usable IP addresses.
474
00:30:17,396 --> 00:30:19,926
And then all of a sudden,
Texas has a need to have a link
475
00:30:19,926 --> 00:30:23,816
to the new Michigan office, router three.
476
00:30:24,716 --> 00:30:26,576
All right here, we've got
another network, you know.
477
00:30:26,576 --> 00:30:27,926
We have a network down here.
478
00:30:27,926 --> 00:30:32,386
Now, of course, we wouldn't use this kind
of subnet mask on the network down here
479
00:30:32,386 --> 00:30:35,026
because you would only be able to
have two devices in that network.
480
00:30:35,026 --> 00:30:36,986
That will be-- that would
be absurd, you're right.
481
00:30:37,226 --> 00:30:40,296
But for the WAN link going
between Texas and Michigan, sure,
482
00:30:40,296 --> 00:30:46,076
let's make that guy 192.5.20.4/30.
483
00:30:46,306 --> 00:30:48,436
Again remember, this represents the network.
484
00:30:48,436 --> 00:30:51,936
So, when I'm writing documentation,
I'm diagramming, I'm saying, "Oh, yeah,
485
00:30:51,936 --> 00:30:58,466
it's the .4 network slash 30, so
he'll be .5 IP address, he'll be .6.
486
00:30:59,976 --> 00:31:01,476
Okay, so how's it feeling?
487
00:31:01,476 --> 00:31:05,886
Are you getting-- get a little water treading
going on over your heads above why you're like,
488
00:31:05,886 --> 00:31:09,826
"Okay, I saw what you did, some of
the pieces are starting to make sense,
489
00:31:09,826 --> 00:31:11,496
make sense, let's do another one."
490
00:31:11,496 --> 00:31:13,436
You know, that-- hopefully,
that's the feeling you're getting.
491
00:31:13,436 --> 00:31:19,016
So, what I'm going to do is change it to where
we're moving beyond Class C only examples.
492
00:31:19,016 --> 00:31:21,956
So, we're going to start with a Class B address.
493
00:31:22,096 --> 00:31:22,786
Now, you remember?
494
00:31:23,006 --> 00:31:27,586
The Class B addresses by default
are slash 16 or 255, 255, 0, 0.
495
00:31:27,586 --> 00:31:31,776
So only the first two octets
represent the network now.
496
00:31:31,776 --> 00:31:35,486
So, let's start there and
see where that leads us.
497
00:31:35,486 --> 00:31:37,896
So, number one, okay.
498
00:31:37,896 --> 00:31:40,366
So, let's look at our situation first.
499
00:31:40,526 --> 00:31:45,256
We have a Class B network, 150.5.0.0.
500
00:31:46,186 --> 00:31:53,876
and we want to break that into 100, kind of 100
individual subnets or 100 individual networks
501
00:31:53,876 --> 00:31:55,696
to disperse around our organization, okay.
502
00:31:55,836 --> 00:31:58,766
So, with that in place, let's start of.
503
00:31:58,766 --> 00:32:00,966
Determine the number of networks
and convert to binary.
504
00:32:01,236 --> 00:32:02,246
Well, it was given to us.
505
00:32:02,246 --> 00:32:03,846
We needed 100 networks.
506
00:32:03,846 --> 00:32:09,716
So let's bring up our binary
charts 64, 32, 16, 8, 4, 2, 1.
507
00:32:10,016 --> 00:32:12,626
All right, so 100, let's use
our shortcut [inaudible].
508
00:32:12,626 --> 00:32:14,036
Our first one goes right there, right?
509
00:32:14,426 --> 00:32:20,796
So, from the last example we did, we know we
can stop because we know that 100 takes 7 bits.
510
00:32:20,956 --> 00:32:23,946
Now, again, if that throws you
off, then, you know, continue on.
511
00:32:23,946 --> 00:32:28,116
I think-- is that 164 plus
32, that'll be 96, right.
512
00:32:28,116 --> 00:32:29,006
Yeah, that should be 100.
513
00:32:29,006 --> 00:32:33,216
So you could figure out the whole binary
value but still, it would still be 7 bits
514
00:32:33,216 --> 00:32:35,456
that we get by the time it's said and done.
515
00:32:35,456 --> 00:32:39,656
So, we're after the number of bits
because we need them in step two.
516
00:32:39,926 --> 00:32:42,546
Reserve bits in the subnet
mask and find your increment.
517
00:32:42,816 --> 00:32:46,016
Now, our subnet mask, and this is why
it's so-- you might be like, "Well,
518
00:32:46,016 --> 00:32:50,446
I'm kind of tired writing 1s and 0s, it's
so super critical that you do especially
519
00:32:50,446 --> 00:32:54,166
when you get to the non-class C examples
'cause you want to see where you're at.
520
00:32:54,426 --> 00:32:58,956
So, one, two, three, four, five, six, seven,
eight, dot, one, two, three, four, five, six,
521
00:32:58,956 --> 00:33:02,586
seven, eight, dot, one, two, three,
four, five, six, seven, eight.
522
00:33:02,936 --> 00:33:06,076
One, two, three, four, five, six, seven, eight.
523
00:33:06,286 --> 00:33:10,056
Good. So that's our subnet mask in
all binary for Class B subnet mask.
524
00:33:10,056 --> 00:33:11,326
That's where we started with this.
525
00:33:11,326 --> 00:33:14,106
So, we have 150.5 that we're working with.
526
00:33:14,106 --> 00:33:20,466
So, I'm looking-- I can't get 100
networks with any less than 7 bits.
527
00:33:20,466 --> 00:33:23,796
And I remember that I'm after networks,
I'm not after a host per network.
528
00:33:23,796 --> 00:33:28,446
So those are the 1s, I need more
1s, how many of them, seven of them.
529
00:33:28,446 --> 00:33:30,996
Now, I'm going to start where the 1s leave off.
530
00:33:30,996 --> 00:33:33,696
One, two-- hang on, I can't do that.
531
00:33:33,696 --> 00:33:36,806
I need another color.
532
00:33:36,996 --> 00:33:41,886
One, two, three, four, five, six, seven, zero.
533
00:33:42,296 --> 00:33:46,286
One, two, three, four, five, six,
seven, eight, I'm super visual.
534
00:33:46,396 --> 00:33:49,226
Everything I do is-- I have to
draw it, I have to write it.
535
00:33:49,386 --> 00:33:49,866
It's funny.
536
00:33:49,866 --> 00:33:52,506
It's-- I'm so-- I'm such a visual learner.
537
00:33:52,716 --> 00:33:55,686
It's to the point of handicapped
to where when somebody talks to me,
538
00:33:55,686 --> 00:33:59,376
if their sentences go beyond like three
sentences, if it's a network situation,
539
00:33:59,376 --> 00:34:00,496
I'm like, "Let's go to a white board."
540
00:34:00,496 --> 00:34:06,076
I have a 2,000 square foot office that I
work in when I'm not working out of my home.
541
00:34:06,456 --> 00:34:10,176
I literally have nine white
boards put up around the office.
542
00:34:10,176 --> 00:34:12,556
Like every room have at least
two white boards on the wall.
543
00:34:12,766 --> 00:34:16,276
You know, like some people put up art, I put
up white boards 'cause I have to do that.
544
00:34:16,276 --> 00:34:20,516
So forgive me when I'm like I
need color, I need something new.
545
00:34:20,516 --> 00:34:22,566
So, I've reserved my 7 bits.
546
00:34:22,566 --> 00:34:28,176
Now, be careful, it's so easy when you're
doing this to think in a Class C. So,
547
00:34:28,346 --> 00:34:32,276
you might have your, you know, the bunch of 1s
and then you got one, two, three, four, five,
548
00:34:32,276 --> 00:34:34,086
six, you know, dot, one, two, three, four, five.
549
00:34:34,086 --> 00:34:37,996
So, right here, sometimes people mistakenly
start in the last octet, you know,
550
00:34:37,996 --> 00:34:39,876
because they're so used to Class C examples
551
00:34:39,876 --> 00:34:43,536
like they would start putting 1s right
there instead of where the 1s leave off.
552
00:34:43,666 --> 00:34:45,256
Always pick up for the 1s leave off.
553
00:34:45,256 --> 00:34:48,836
You don't want to have 1s here and nothing
there, that-- it just doesn't work that way.
554
00:34:49,296 --> 00:34:53,216
So, at this point, we know what
our subnet mask is going to be.
555
00:34:53,266 --> 00:34:58,506
It's now 255.255 dot-- I'm
looking at that third octet now.
556
00:34:58,506 --> 00:35:03,916
Now, again, you can add all these numbers
up, 128, 64, 32 or you can just remember
557
00:35:03,916 --> 00:35:06,816
that it's 255 and I don't have a one.
558
00:35:06,946 --> 00:35:10,836
So that would be 254.0 is our subnet mask.
559
00:35:10,836 --> 00:35:12,386
CIDR notation.
560
00:35:12,386 --> 00:35:16,976
Originally, we had a slash 16
and now we graduated ourselves
561
00:35:16,976 --> 00:35:22,256
to a slash 23 'cause we added
7 bits on to our 16 right here.
562
00:35:22,256 --> 00:35:27,246
So, that's our new subnet mask insider, that's
our new subnet mask in decimal notation.
563
00:35:27,586 --> 00:35:28,606
What's our increment?
564
00:35:28,806 --> 00:35:33,866
Another place where a mistake could easily
be caused by kind of logically thinking--
565
00:35:33,866 --> 00:35:36,436
you're thinking, "Okay, my
increments are one, two, three, four,
566
00:35:36,436 --> 00:35:37,876
you know, you start-- not one, two, three.
567
00:35:37,876 --> 00:35:39,296
One, two, four, eight, 16.
568
00:35:39,446 --> 00:35:42,516
You start counting and you're like okay, 120,
so this must be-- you see what I'm saying?
569
00:35:42,516 --> 00:35:44,516
256 but no.
570
00:35:44,626 --> 00:35:46,776
That's not the way to think about it.
571
00:35:46,776 --> 00:35:48,146
Don't count from far right.
572
00:35:48,436 --> 00:35:52,236
Every octet is a new set of increments, right?
573
00:35:52,236 --> 00:35:58,286
So you've got one, two, four, eight, 16,
32, 64, 128 here, then we start over.
574
00:35:58,416 --> 00:36:02,476
One, two, two, four, eight,
and so on and so forth.
575
00:36:02,476 --> 00:36:07,606
So, our increment is a 2, right?
576
00:36:07,606 --> 00:36:10,466
The lowest network bit converted
back to a decimal number.
577
00:36:10,906 --> 00:36:11,866
Good. Okay.
578
00:36:11,866 --> 00:36:17,386
So now-- so it's working out, I mean, I'm just
kind of showing you the little pieces here
579
00:36:17,386 --> 00:36:21,336
and there where you could trip up but it's
the same exact thing as it was previously.
580
00:36:21,336 --> 00:36:23,246
So, now let's write our network ranges.
581
00:36:23,246 --> 00:36:28,556
So we've got 150.5.0.0 because
that's what we were given.
582
00:36:28,976 --> 00:36:29,876
Now, be careful.
583
00:36:30,186 --> 00:36:35,456
I need to add my increment, add
my two in the octet where it's at.
584
00:36:36,146 --> 00:36:40,726
Now, I'm not working in this octet, I'm
working in this octet, the third octet.
585
00:36:40,726 --> 00:36:42,476
So, that's where my 2 gets added.
586
00:36:42,476 --> 00:36:50,376
150.5.2.0, 150.5.4.0.
587
00:36:50,596 --> 00:36:51,156
You see what I'm saying?
588
00:36:51,156 --> 00:36:56,196
150.5.6.0 and down and down
and down we go nonetheless.
589
00:36:57,556 --> 00:36:58,726
Good, good?
590
00:36:58,816 --> 00:37:04,186
Okay. Okay, last place where you could easily
trip up in something like this is to look at it
591
00:37:04,186 --> 00:37:08,146
and go, okay, this is going to go
through, you know, so my range,
592
00:37:08,146 --> 00:37:13,896
the usable addresses are going to go
through 150.5, okay subtract 1, right?
593
00:37:13,896 --> 00:37:20,496
So, .1.0. That's actually not right.
594
00:37:21,316 --> 00:37:23,236
"Well, why not, Jeremy?
595
00:37:23,456 --> 00:37:24,036
What's wrong with that?"
596
00:37:24,196 --> 00:37:34,376
Well, my question is, if this one ends at
150.5.1.0, and this one starts at 150.5.2.0,
597
00:37:34,746 --> 00:37:40,336
so this is right, this is the end, this
is the begin of the next range, all right?
598
00:37:40,336 --> 00:37:40,696
Are you following?
599
00:37:41,146 --> 00:37:46,286
Where does 150.5.1.50 fit?
600
00:37:47,116 --> 00:37:48,566
Well, you're like, "Well, it's in the first."
601
00:37:48,566 --> 00:37:49,596
No, I'm sorry.
602
00:37:49,596 --> 00:37:51,786
Our range ended at 0 there.
603
00:37:51,996 --> 00:37:54,836
That 50 is greater then 0 and
you go "Well, it's over here."
604
00:37:54,836 --> 00:37:56,136
No, that started at 2.
605
00:37:56,136 --> 00:37:58,146
So, where does that guy fit?
606
00:37:58,296 --> 00:38:04,916
Where's 150.1 dot-- well, anything,
150.5.1.200 fit, where does fit?
607
00:38:04,916 --> 00:38:05,636
It doesn't.
608
00:38:05,636 --> 00:38:07,646
We left them out in the cold.
609
00:38:07,646 --> 00:38:09,806
So, we have to go back, we
have to revise our numbers.
610
00:38:09,806 --> 00:38:11,456
Let me just wipe these guys off.
611
00:38:11,456 --> 00:38:14,066
Revise our numbers here to
say, no, no, no [inaudible].
612
00:38:14,066 --> 00:38:15,966
Let's get you out.
613
00:38:16,156 --> 00:38:22,906
This actually ends at 150.5.1.255.
614
00:38:23,556 --> 00:38:27,676
That's the actual-- last that I'd like-- think
of it as some bizarre lot-- math problem.
615
00:38:27,676 --> 00:38:31,086
Remember when you're first learning
math and they go, "Okay, 19,
616
00:38:31,266 --> 00:38:33,276
what happens if I add one to that?"
617
00:38:33,586 --> 00:38:37,126
And I mean, you got to reduce yourself
back to an elementary mindset, right?
618
00:38:37,266 --> 00:38:41,246
You kind of like, "Oh, well, I can't have
10 there because I can only have one digit
619
00:38:41,286 --> 00:38:45,556
so I have to just kind of 0 it out
and carry the 1 if you will, right?
620
00:38:45,556 --> 00:38:46,986
So, we're in 20.
621
00:38:46,986 --> 00:38:49,506
So, think of it in like bizarre
math world, right?
622
00:38:49,666 --> 00:38:54,216
You know that 255 is like your 9 because you
can't have any more than that with 8 bits.
623
00:38:54,216 --> 00:38:56,886
So, if we add 1 to that, what happens?
624
00:38:57,216 --> 00:38:58,936
Well, we can have 256.
625
00:38:58,936 --> 00:39:01,536
It doesn't-- that value doesn't
exist with 8 bits.
626
00:39:01,536 --> 00:39:05,556
So, it kind of zeros out and carries
the 1 so you're down to 2 here, right?
627
00:39:05,556 --> 00:39:07,756
So, [laughs] if that works for you, oh great.
628
00:39:07,756 --> 00:39:09,086
If not, then forget I ever said it.
629
00:39:09,086 --> 00:39:12,536
So, that's going to follow that
same trend the whole way down.
630
00:39:12,536 --> 00:39:18,406
This goes through 150.5.3.255, sweet.
631
00:39:18,406 --> 00:39:20,396
Through 150, you see how this is working?
632
00:39:20,396 --> 00:39:25,256
5.5.255, cool, down and down and down we go.
633
00:39:26,486 --> 00:39:31,326
Come on, you got to be looking right
and go on, "Okay, okay I'm feeling it.
634
00:39:31,326 --> 00:39:34,506
I'm seeing how theses pieces are
starting to fit in the place, right?"
635
00:39:34,506 --> 00:39:40,226
If not, I would say, stop here, rewind, go
back through it a few more times because it--
636
00:39:40,226 --> 00:39:45,206
like at this point, I would suggests it would
be soaking in where you're like, "Okay, okay.
637
00:39:45,206 --> 00:39:50,626
I'm starting to see how this-- I don't know
why these weird things like this horse rides."
638
00:39:50,626 --> 00:39:53,706
So this is like [laughs] I know, what I mean
like, I'm starting to see the feel of it.
639
00:39:53,706 --> 00:39:56,496
Okay. Now let me throw something else at you.
640
00:39:56,566 --> 00:39:58,076
I'm like, [laughs] "Okay, you think you got it?"
641
00:39:58,076 --> 00:39:59,256
Well, let me show you something.
642
00:39:59,256 --> 00:40:01,646
So, somewhere in the middle
of this range, right?
643
00:40:02,046 --> 00:40:08,576
You're going to run into
the IP address 150.5.0.255,
644
00:40:09,966 --> 00:40:12,416
right, somewhere in the middle there.
645
00:40:12,446 --> 00:40:18,426
You're also going to run into the IP address
150.5.1.0, that's right next to that guy right,
646
00:40:18,426 --> 00:40:20,536
right, kind of in the middle of that range.
647
00:40:20,536 --> 00:40:24,726
So, again, it's let put this back
in the terms of network situation.
648
00:40:26,286 --> 00:40:28,736
We've got computers connected to a router.
649
00:40:28,736 --> 00:40:30,776
I mean, this company needed 100 networks.
650
00:40:30,776 --> 00:40:35,776
So maybe it's something like this where
they've got, you know, corporate headquarters
651
00:40:35,906 --> 00:40:39,156
and I they've got all these kind of networks
over there and computers and all that,
652
00:40:39,156 --> 00:40:40,806
and that corporate headquarters goes to all
653
00:40:40,806 --> 00:40:43,156
of these branch offices like--
let's, you know, identify.
654
00:40:43,156 --> 00:40:49,086
Let's-- maybe it's like a wells
Fargo Bank or a State Farm Insurance,
655
00:40:49,086 --> 00:40:52,166
I'm just throwing companies out there that
I would assume would follow this model
656
00:40:52,166 --> 00:40:54,756
to where they have kind of
corporate headquarters
657
00:40:54,886 --> 00:40:57,946
and then all these little branch
offices, street mall, you know,
658
00:40:57,946 --> 00:41:00,896
ATM machines, I mean, it's funny.
659
00:41:01,206 --> 00:41:06,346
When you, you know, how-- when you get
a car like you're driving a new car
660
00:41:06,346 --> 00:41:10,616
and you're looking around, you're like, "Hey,
I see like so many of these cars on the road.
661
00:41:10,616 --> 00:41:14,866
It's not that there's anymore, it's just now
that you have that car, you see it everywhere.
662
00:41:14,976 --> 00:41:19,536
It's the same thing, when you start getting at
the network world, you'll be walking in a store
663
00:41:19,666 --> 00:41:21,446
and you're like, "I wonder how
they do the network for this?"
664
00:41:21,446 --> 00:41:23,036
I want to-- like I walked in Walmart.
665
00:41:23,036 --> 00:41:25,826
I don't see stuff on the shelf
anymore, it's like the matrix.
666
00:41:25,826 --> 00:41:27,986
I just see, you know, binary 1s.
667
00:41:27,986 --> 00:41:30,416
You know, I'm like, "How does Walmart?"
668
00:41:30,416 --> 00:41:31,836
I see a guy with hand scanner.
669
00:41:31,836 --> 00:41:35,416
I'm like, "Oh, that's connected to a
WIFI network, I wonder how they design,"
670
00:41:35,566 --> 00:41:36,746
like that's the kind of thought you have.
671
00:41:36,746 --> 00:41:43,026
So this is Walmart, right, and this is store
1, store 2, store 3, all that kind of stuff,
672
00:41:43,026 --> 00:41:48,186
so all these different stores, so, you're like,
"Jeremy, come back to us," I'm back, okay.
673
00:41:48,276 --> 00:41:52,026
So, this network one gets
assigned to store 1, right?
674
00:41:52,026 --> 00:41:59,266
So, can I go to this computer at that store or
that hand scanner or whatever device that is
675
00:41:59,496 --> 00:42:04,206
and give it the IP address 150.5.0.255.
676
00:42:04,516 --> 00:42:08,766
Can I assign this IP address to that computer?
677
00:42:08,906 --> 00:42:10,846
[Inaudible], did you get it?
678
00:42:10,846 --> 00:42:12,816
Yes, you can.
679
00:42:13,616 --> 00:42:16,136
[laughs] No, and somebody like, "No, but it's--
680
00:42:16,316 --> 00:42:20,816
but no, it's 255, you can't use
255, isn't that the broadcast?"
681
00:42:20,816 --> 00:42:27,566
No, once we've gone beyond a Class C example,
we've come into a world where there--
682
00:42:27,606 --> 00:42:32,006
we're kind of moving between
big ranges if you will
683
00:42:32,006 --> 00:42:36,246
to where there's only one
network and that's 150.5.0.0.
684
00:42:36,436 --> 00:42:41,296
And there's only one broadcast
on this network, 150.5.1.255,
685
00:42:41,296 --> 00:42:43,886
everything in the middle is fair game.
686
00:42:44,086 --> 00:42:46,516
So, yes, this is a valid address.
687
00:42:46,856 --> 00:42:48,836
Yes, this is a valid address.
688
00:42:48,836 --> 00:42:50,356
You can't, now it's going to feel really weird.
689
00:42:50,356 --> 00:42:52,116
You're going to be like,
"This ain't going to work out.
690
00:42:52,116 --> 00:42:53,556
I can feel it now, it's not going to work."
691
00:42:53,656 --> 00:42:54,096
It will work.
692
00:42:54,406 --> 00:42:57,496
It will work as long as you
give it this subnet mask
693
00:42:57,646 --> 00:43:00,906
because that tells the computer
exactly what the range is.
694
00:43:01,156 --> 00:43:05,456
So, I mean same thing down here, you would
run into, you know, in this range right here,
695
00:43:05,456 --> 00:43:09,516
you'd run into 150.5.4.255, somewhere in there.
696
00:43:10,346 --> 00:43:11,006
Does it work?
697
00:43:11,006 --> 00:43:12,476
Can I assign that to a device?
698
00:43:12,756 --> 00:43:15,376
Yes, you ca and it will work.
699
00:43:15,806 --> 00:43:17,976
That's the power that we have with these ranges.
700
00:43:17,976 --> 00:43:22,366
So, already, I know some of you are real
world, some of you are really heavy focused
701
00:43:22,366 --> 00:43:27,336
on the certification exam, if your certification
focus already be thinking of the test question.
702
00:43:27,636 --> 00:43:31,206
Based on this IP address and
based on this subnet mask,
703
00:43:31,566 --> 00:43:34,926
which of the following are valid addresses?
704
00:43:34,926 --> 00:43:37,096
And I guarantee you those guys
are going to show up in the list
705
00:43:37,096 --> 00:43:38,576
and be, "Oh, no, those aren't valid."
706
00:43:38,776 --> 00:43:43,096
Oh, yes they are depending on the subnet mask
that you use, they definitely can be valid.
707
00:43:44,776 --> 00:43:49,446
Okay, one last example, this
one a Class A example.
708
00:43:49,916 --> 00:43:54,696
We've got the 10 network, 10.0.0.0
and we need a thousand networks.
709
00:43:54,696 --> 00:44:00,586
Now you remember class A subnet mask gets
a slash 8 or 255.0.0.0 and we need to break
710
00:44:00,586 --> 00:44:03,746
that into a whole big number of
networks, is that even possible?
711
00:44:03,966 --> 00:44:04,956
Well, let's find out.
712
00:44:05,046 --> 00:44:10,356
First off, we need to determine the number
of networks and convert it to binary.
713
00:44:10,356 --> 00:44:13,546
So, I'm going to take a thousand
subnets equals--
714
00:44:13,546 --> 00:44:22,166
okay, wait a second, we've gone outside of
our 128, 64 world or 8 bits 32, 16, 8, 4, 2,
715
00:44:22,166 --> 00:44:27,686
1 'cause we know the biggest number that we
can get with this is 255, so can we do it?
716
00:44:28,236 --> 00:44:30,176
Yeah, we just need to stretch a little bit more.
717
00:44:30,506 --> 00:44:34,596
So I'm going to go to the next decrement, 256.
718
00:44:34,596 --> 00:44:40,116
If I multiply, you know, powers of 2 to
the power of 8 is 256 or 128 times 2,
719
00:44:40,396 --> 00:44:43,476
then we multiply that by
2 and that would be 512.
720
00:44:43,476 --> 00:44:44,846
Okay, is that big enough?
721
00:44:44,846 --> 00:44:47,696
Well, let's multiple that
by 2 and we go, okay, 1,024.
722
00:44:47,696 --> 00:44:49,966
Okay, we've exceeded a thousand network.
723
00:44:49,966 --> 00:44:55,046
So I know my 1 can't go right here, that's
not possible because I can't subtract 1,024
724
00:44:55,046 --> 00:44:58,026
from 1,000, so my first one goes right there.
725
00:44:58,456 --> 00:45:04,746
Now again, you can figure out the entire
binary number for 1,000 but I would say,
726
00:45:04,826 --> 00:45:08,786
especially in a number this big, it makes
it a lot faster for you to say, okay, well,
727
00:45:08,856 --> 00:45:11,936
how many bits did it take
to get the number 1,000?
728
00:45:11,936 --> 00:45:18,306
Well, we had our 8, 9, 10,
a thousand is 10 bits.
729
00:45:19,606 --> 00:45:24,676
All right, so reserve bits in the mask and
find the increment, our original subnet mask
730
00:45:24,676 --> 00:45:28,446
because it was class A is 255.0.0.0.
731
00:45:28,866 --> 00:45:32,166
In binary, it looks like this two,
three, four, five, six, seven, eight.
732
00:45:32,636 --> 00:45:34,696
Two, three, four, five, six, seven, eight.
733
00:45:34,796 --> 00:45:37,386
Now, remember all these 0s are ours.
734
00:45:37,606 --> 00:45:39,806
It's our playground to work with.
735
00:45:39,996 --> 00:45:43,536
I got 2 [inaudible] either.
736
00:45:43,596 --> 00:45:45,526
Yeah, [inaudible], there we go.
737
00:45:45,526 --> 00:45:47,766
So, we've got our subnet mask in all binary.
738
00:45:47,966 --> 00:45:52,836
Now, we go back to the question, what do we
need, 1,000 hosts per network or 1,000 networks?
739
00:45:52,936 --> 00:45:54,406
Well, in this case 1,000 networks.
740
00:45:54,406 --> 00:46:00,456
We know that to get the number 1,000, it's
10 bits and we know that network bits are 1s,
741
00:46:00,636 --> 00:46:02,736
not 0s in the binary scheme of thing.
742
00:46:02,736 --> 00:46:10,386
So, we pick up right where the 1s leave off and
we say, one, two, three, four, five, six, seven,
743
00:46:10,556 --> 00:46:14,896
eight, oh I didn't line them up exactly but
that's eight, and lines up to the eight,
744
00:46:15,156 --> 00:46:20,866
dot nine, ten 'cause we needed
10 bits to get the number 1,000.
745
00:46:20,866 --> 00:46:22,956
I can't do this with any less then 10,
746
00:46:22,956 --> 00:46:25,876
so we actually cross the dotted
line if you will into that.
747
00:46:26,076 --> 00:46:26,976
The rest of these can stay 0.
748
00:46:27,516 --> 00:46:32,866
[ Pause ]
749
00:46:33,366 --> 00:46:34,656
That's our new subnet mask.
750
00:46:35,166 --> 00:46:41,056
So we've added 10 network bits, so
our new subnet mask goes 255.255 dot--
751
00:46:41,056 --> 00:46:46,696
let's see what this one, 128 plus 64 since we
have kind of those two lit up in this octet.
752
00:46:46,696 --> 00:46:54,366
So, that would be 192.0, so that's the decimal
version or we're moving from a slash 8 up here
753
00:46:54,586 --> 00:47:00,526
down to a slash-- that will be slash 8, slash
16, the first two, 17, 18 'cause we added two
754
00:47:00,526 --> 00:47:05,356
in that last one, so we're going
to a slash 18 subnet mask, good.
755
00:47:06,606 --> 00:47:09,176
So, now the question what is our increment?
756
00:47:09,416 --> 00:47:10,906
Well, our increment is right here.
757
00:47:11,496 --> 00:47:13,186
Lowest network bit back in binary.
758
00:47:13,186 --> 00:47:16,666
Again, nothing funky, every single
octet restarts the increment,
759
00:47:16,666 --> 00:47:20,766
so that's a 64, like that.
760
00:47:21,346 --> 00:47:25,356
And now, we just start adding that
increment to find our network ranges.
761
00:47:25,356 --> 00:47:28,286
So, I'm going to start with Class
A. Let's see where do I begin?
762
00:47:28,556 --> 00:47:33,636
10.0.0.0 is what we we're given, 10.0.0.0, okay.
763
00:47:33,636 --> 00:47:35,036
What octet is our increment in?
764
00:47:35,816 --> 00:47:37,586
This one, the third one over, right?
765
00:47:37,586 --> 00:47:42,866
So, I'm going 10.0.64.0.
766
00:47:43,966 --> 00:47:50,836
Whoa, 10.0.128.0, I'm adding
64 in that third octet.
767
00:47:51,046 --> 00:47:57,126
10.0.192.0 and down and down we go.
768
00:47:57,126 --> 00:48:01,346
Now, I'm actually going to come back to my down
and down and down statement in just a moment,
769
00:48:01,606 --> 00:48:04,426
but let me fill in the end ranges first.
770
00:48:04,426 --> 00:48:07,966
So, this one is going to go through 10.0 dot--
771
00:48:07,966 --> 00:48:11,726
now remember from the last one,
this little trick 63 dot what?
772
00:48:12,296 --> 00:48:21,036
255. This one goes through 10.0.127.255.
773
00:48:21,036 --> 00:48:25,246
We can't cut off that end range, so we're--
just like the last one, we're going through that
774
00:48:25,476 --> 00:48:27,126
and we would continue this way all the way down.
775
00:48:27,126 --> 00:48:29,396
This goes through 191.255.
776
00:48:29,396 --> 00:48:31,656
Again, just the last two
octets that I'm putting in.
777
00:48:31,656 --> 00:48:34,106
Now, let me ask a question on this lesson.
778
00:48:34,106 --> 00:48:35,536
I want to-- this is what I want to come back to.
779
00:48:35,916 --> 00:48:39,836
What do you get if you add 64 to 192?
780
00:48:40,966 --> 00:48:41,356
Let's do it.
781
00:48:41,356 --> 00:48:48,416
192 plus 64 equals 6, 5,
carry the 1, that'll be 2.
782
00:48:48,416 --> 00:48:51,476
Whoa, buddy, hey wait a second.
783
00:48:51,476 --> 00:48:58,086
We-- so you're saying if we keep going with
this increment, we're going to get 10.0.256.0.
784
00:48:58,086 --> 00:48:59,896
No, that's broken, we can't do that.
785
00:49:00,736 --> 00:49:03,256
Well, if you hit that point, don't worry.
786
00:49:03,256 --> 00:49:10,196
You haven't done anything wrong, that just
tells you've reached the end of an octet.
787
00:49:10,196 --> 00:49:12,466
So, hang on, before we do
anything more, let's fill in--
788
00:49:12,466 --> 00:49:15,026
what would the last IP address
for this range be?
789
00:49:15,026 --> 00:49:18,876
It will 10.0 dot-- what's subtract 1 from 256?
790
00:49:18,876 --> 00:49:23,226
255.255. Just-- I should erase this
791
00:49:23,226 --> 00:49:26,826
and write the whole thing just
so it looks nice and consistent.
792
00:49:26,826 --> 00:49:31,586
So, this goes to 10.0 dot--
what, 191.255, right?
793
00:49:31,816 --> 00:49:32,816
So go on with this.
794
00:49:32,816 --> 00:49:35,946
This goes 255.255 right there.
795
00:49:35,946 --> 00:49:38,106
So, what that tells you is you reached the end.
796
00:49:38,676 --> 00:49:40,196
Now, wait a second.
797
00:49:40,196 --> 00:49:41,366
The end, what do you mean?
798
00:49:41,496 --> 00:49:44,836
We're after a thousand networks
and we only got four right?
799
00:49:45,126 --> 00:49:48,236
How do we get a thousand networks
when we're at the end right there?
800
00:49:48,406 --> 00:49:52,436
Well, we're at the end of our
first kind of major octet.
801
00:49:52,436 --> 00:49:54,666
Our first-- we're at the end of the 0s.
802
00:49:54,986 --> 00:49:57,166
So again, think of that bizarre math world.
803
00:49:57,166 --> 00:50:00,476
If I said plus 1, you know,
[inaudible] and then I say, "Okay,
804
00:50:00,476 --> 00:50:01,976
what's the next IP address after that?"
805
00:50:02,276 --> 00:50:04,626
Well, 256 would zero out, carry the 1.
806
00:50:04,836 --> 00:50:08,686
So this would zero out, carry
the 1 and we move over to 10.1.
807
00:50:09,466 --> 00:50:10,386
And see what we're going here?
808
00:50:10,386 --> 00:50:15,666
So, there really is no 10.0.256
dot-- oh, I can't do that.
809
00:50:15,936 --> 00:50:18,726
There is no 10.0.256.0.
810
00:50:18,986 --> 00:50:25,526
The next one will actually go to
10.1.0.0, that's our next IP address,
811
00:50:25,526 --> 00:50:30,296
and then we start the whole thing all
over again, 10.1.64, 10.1.128, you know,
812
00:50:30,296 --> 00:50:32,276
just kind of keep going down with that counting.
813
00:50:32,376 --> 00:50:36,056
And once you see the scheme of
how this works and I'm squeezing
814
00:50:36,056 --> 00:50:39,346
at the bottom, 10.1.128 is there.
815
00:50:39,346 --> 00:50:43,086
You see the scheme, it just--
and now, you start looking, oh,
816
00:50:43,086 --> 00:50:45,096
that's how we get a thousand networks.
817
00:50:45,096 --> 00:50:48,866
Every single one of these octets all the
way up to 255 gets four networks a piece,
818
00:50:49,076 --> 00:50:52,276
that makes sense, you know, it's where--
now I can see where that fits in.
819
00:50:52,276 --> 00:50:54,646
So, this is just kind of repeats itself.
820
00:50:54,646 --> 00:50:56,146
That's why I wanted to do this example.
821
00:50:56,146 --> 00:50:59,016
You might say, well, we've already
seen kind of a Class B. Well,
822
00:50:59,016 --> 00:51:00,296
I wanted to show you again breaking
823
00:51:00,296 --> 00:51:04,216
that paradigm a little bit more
to see all of that is possible.
824
00:51:04,676 --> 00:51:07,516
Now, there're always two levels of learning.
825
00:51:08,086 --> 00:51:13,456
There's one where you can watch somebody who's
explaining it, like me, and go, "Okay, I get it.
826
00:51:13,456 --> 00:51:14,586
I kind of see what you're doing.
827
00:51:14,586 --> 00:51:17,366
I see what you're following and
that-- like that's a major milestone."
828
00:51:17,606 --> 00:51:19,396
Congratulations if you're at that point.
829
00:51:19,396 --> 00:51:22,706
If you're not at that point, then, you
know, rewind, go back through it again,
830
00:51:22,706 --> 00:51:26,186
just keep watching until you're like, "Oh,
that-- it's starting to click, it makes sense."
831
00:51:26,306 --> 00:51:31,026
But there's a second level of learning that
you absolutely need to reach with every concept
832
00:51:31,026 --> 00:51:36,086
in the Cisco world, but especially this one,
and that is the level of doing it yourself.
833
00:51:36,136 --> 00:51:39,786
So right now, I want to transfer you
to-- from level one to level two,
834
00:51:39,786 --> 00:51:41,656
by giving you this homework assignment.
835
00:51:41,656 --> 00:51:45,586
You can see all it is-- I put
the class of network that is.
836
00:51:45,586 --> 00:51:49,386
So, this is a Class C network,
Class B network, Class A network.
837
00:51:49,386 --> 00:51:54,296
So, I've got four examples for you to
work through, and to check your work,
838
00:51:54,296 --> 00:51:58,376
I'm going to include a supplemental
file with this nugget.
839
00:51:58,376 --> 00:51:59,926
You can actually download it.
840
00:51:59,926 --> 00:52:02,996
I think it's-- I think that the supplements
are all included in one big zip file,
841
00:52:02,996 --> 00:52:05,096
but you can download it, so
you're able to check the work.
842
00:52:05,096 --> 00:52:09,766
And I'm going to write this file in such
a way that it's kind of step by step.
843
00:52:09,766 --> 00:52:11,686
It's broken down as if I was explain--
844
00:52:11,716 --> 00:52:15,626
it's the best I can do in writing
style to explain what I'm doing
845
00:52:15,626 --> 00:52:16,756
as I go through each one of them.
846
00:52:16,756 --> 00:52:21,206
So, right now-- before its seeps out of
your mind, sit down with a piece of paper
847
00:52:21,206 --> 00:52:23,116
and see if you can work through these.
848
00:52:23,116 --> 00:52:28,406
Try not to look at the answer, because these
are the four examples that I'm giving you,
849
00:52:28,406 --> 00:52:31,496
try not to look in, go back through
the lecture and see if you can kind
850
00:52:31,496 --> 00:52:36,526
of piece together the steps and get through
them all yourself, and then check your work.
851
00:52:36,876 --> 00:52:41,486
Also, realize that there are
literally thousands of free examples
852
00:52:41,486 --> 00:52:44,066
of subnetting questions out
there in the internet.
853
00:52:44,066 --> 00:52:46,716
The world knows that this
is a hard topic to get.
854
00:52:47,246 --> 00:52:51,106
So, you will find-- if you just go on
Google and type in subnetting examples,
855
00:52:51,416 --> 00:52:54,486
you'll find slide after slide after
slide that gives you practice problems
856
00:52:54,486 --> 00:52:56,996
and so on that you're able to
work through and check your work.
857
00:52:58,066 --> 00:53:01,126
Well, that leads us to the
end of subnetting style 1
858
00:53:01,126 --> 00:53:04,586
which is creating subnets
based on network requirements.
859
00:53:04,816 --> 00:53:08,806
As we move in to the next nugget, we'll start
expanding on different styles of subnetting,
860
00:53:08,806 --> 00:53:12,436
different styles of examples, but for now,
I hope this has been informative for you
861
00:53:12,436 --> 00:53:14,016
and I'd like to thank you for viewing.
83708
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