# Subnetting for Hosts

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00:00

we've addressed how to use our sub net masks to provide us additional subnets or networks. So we'll modify that sub net mask is needed and get the formula where two to the power of X equals the number of subnets you've created.

00:13

Now we'll switch our focus and discuss hosts per network.

00:18

When we're working with Subnets. Remember, we're working with ones and when we're working with hosts were working with zeros.

00:25

So when somebody for hosts we'll do things a bit differently

00:29

in Submitting for host will focus on binary zeros

00:32

when stealing bits for sub nuts. We go left to right, and when stealing for hosts, we go right to left.

00:39

Take note.

00:41

The formula for the number of hosts needed is X to the power of two minus two.

00:45

Remember, we have to subtract two for the network, and broadcast address is

00:50

also remember that when you figure out the number of hosts or binary zeros you'll be using, you'll have a 32 bit I p address.

00:58

If I need five binary zeros to support hosts, the remaining 27 will be set to one.

01:06

Let's take a look at this helpful chart,

01:08

which will replace the submitting chart.

01:11

When working with hosts, we'll look at things differently and use this chart instead.

01:18

Using the chart I just shared. Let's work on a question together.

01:22

What sub net mask what I use to produce as many networks as possible, with a minimum of 20 hosts per sub net.

01:30

Let's go back to the chart

01:30

that I recommend Memorizing

01:33

I'm looking for 20 hosts per submit

01:36

and four bits set to zero isn't enough.

01:38

But five bits set to zero will give me 30 hosts in each submit.

01:44

If five are set to zero, the remaining 27 are set to one.

01:48

Use your slash 27 to indicate the number of binary ones in your sub net mask.

01:55

Try the next questions. What network would I use to produce as many networks as possible with a minimum of 64 hosts per submit?

02:04

Pause the video and see how you do.

02:07

Let's take a look at the answers.

02:08

We've already went through the first one together

02:10

for the next one. I need to produce as many networks as possible, and I need 64 hosts per subnets.

02:19

I like to use my chart to answer these questions,

02:22

I need support for 64 hosts.

02:23

Six isn't enough,

02:25

so we'll go up to seven.

02:27

We'll set seven bits to zero because we're talking about hosts,

02:30

meaning we'll have a slash 25 sub net mask with 25 bits set to one in our sub net mask.

02:38

What would be the sub net mask to produce as many networks as possible? With a minimum of 600 hosts per subnets

02:45

going back to our chart, nine bits will not be enough.

02:49

The next step is to set 10 bits to zero,

02:52

which would give me support for 1022 hosts.

02:54

Remember that it's important.

02:58

Now we'll have 10 bits at 20

03:00

with 22 bit set to one so slash 22.

03:05

Finally, the sub net mask for Class A

03:07

as many networks as possible with a minimum of 45 hosts. Prayer said that

03:13

to support 45 hosts, I'll have six bits set to zero with this last 26 sub net mask.

03:19

The trick is having this chart.

03:22

So what would the sub net mask for Class A B?

03:25

We said the answer for class a sash 26. I hope you did okay with these questions.

03:30

Remember, when dealing with hosts or work with zeros,

03:35

figure out how many zeros you need and the rest will be binary ones.

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