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OK, I know there are a lot of terms and conditions, so let's just break it down with a real world

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scenario.

3
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Although the standard for A and B class network specify eight and 16 bit mask's respectively, it's

4
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common to assign non-standard masks for subnet, resulting in much more limited address spaces.

5
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For example, using 10 dot WSDOT y y zero size 24 results in 256 host company subnets.

6
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Right.

7
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So this is done for scalability and of course, security.

8
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OK, so we're the system administrators in Company X and ready to build.

9
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We have decided to use one nine two one six eight Eckstut acts as a private IP address base for our

10
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company.

11
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If we use the natural mask 255 255 zero zero, that means we use the first 16 bits for network ID.

12
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And we'll have a single network.

13
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So in this case, we can address sixty five thousand five hundred and thirty six devices in this network.

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Of course, the first type in the last IP were not allowed to use, so the number of IP addresses actually

15
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sixty five thousand five hundred thirty six minus two, you do the math, but in practice, for ease

16
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of use, it's pretty much used as the power of two.

17
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So you can use an IP address in this network from one nine two one six eight zero to one to one nine

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two to one six eight two five 5.2 five four.

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But we need to have different networks, one for the managers, one for the developers, one for the

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servers, et cetera.

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So for the sake of our youth and our sanity, let's use the next eight bits for subnets.

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In this case, we have a subnet mask of 255, 255, 255, got 5.0.

23
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Eight bits for subnet and 24 bits for the network I.D. in total, eight bits left for addressing the

24
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devices under the subnets.

25
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So as a result.

26
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We can create 256 subnet.

27
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And address 256 devices for each one.

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Now we have 256 address ranges for 256 sub networks.

29
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So the table here shows a few examples of our potential subnetwork.

30
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The red colored blocks are added to the network ID as subnet identifiers, the rest of the eight bits

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are used as the host IDs.

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In the four block decimal notation, the third block identifies a subnetwork and the last block identifies

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the host, so breaking it down, it's much simpler now.

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Excellent.

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Let's move on.