# Subnetting

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Time
41 minutes
Difficulty
Intermediate
CEU/CPE
1
Video Transcription
00:00
Hello. My name is Dustin and welcome to networking.
00:03
So what is subheading
00:05
sub? Nothing is creating multiple logical networks that exists within a single class A, B or C network.
00:13
Without submitting, you would only be able to use one network, which is pretty unrealistic and not very efficient.
00:21
So submitting is really a kind of complex subject. So in this module, we're just gonna go over some basic examples of sudden submitting. But before we get into some netting, we need to understand how I P addresses work.
00:35
So we now know that all I B V four addresses are 32 bits containing four octet ce of eight bits each
00:44
Each octet can then range in number from zero
00:48
22 55 or
00:52
00000000 through
00:58
11111111 in binary.
01:03
So we're gonna start off with some basic binary.
01:07
Binary is either a one or a zero, so the switch is either on or off.
01:14
You can see in the table. We've got on the slide here that we've got a decimal numbers up top and binary numbers on the bottom.
01:23
The binary. I'm sorry. The decimal numbers of top represent two to the power.
01:32
So, um, the right most bit, which is the least significant is 20 power, which is one
01:38
going left. We've got to the first Paris two than 48 16 32 64 1 28
01:49
So each column in the table represents one bit.
01:53
The top row on the table is your decimal numbers. And like we discussed, it's two to the 7th 2 to the sixth and all the way down, going from left to right.
02:05
The bottom of the table is for your binary numbers. Each column can either be a one or a zero.
02:12
If it's a zero, you can go on to the next one.
02:15
If it's a one, that means we need to add that number.
02:19
So 1 28 and binary would be one, followed by seven zeroes.
02:25
16 would be 0001
02:30
0000
02:35
2 55 which is the highest number of you. Remember, in an I P. D four address would be all ones.
02:43
Remember that you always wanna work from the left to the right. And this table is what helped me get through my net. Plus in my C, c and A um, it really helps break binary down. So if you can memorize this real quick table, it's really easy to dry out.
03:00
You'll be able to convert from binary and decimal in no time.
03:04
When I took my network plus and like I said, my C, C and A. This is the first thing I did with my note pages. Recreate this table for any decimal. The by an area of binary two decimal conversions. It just makes it really easy to do it quickly without a calculator.
03:23
So it's important to remember that an I P address and a sub net mask give you both a network address and the device address.
03:31
Now that we've got a pretty good grasp on converting from decimal binary in back, let's go over some real common sub nets. You'll see
03:39
the 1st 1 is a private class. A range, which is, if you remember, is 10.0 dot 0.0 through 10.55 to 35 to 55. The standard sub net on a Class A range is 2 55.0 dot 0.0
03:59
in decimal.
04:00
Well, if you remember, um, all ones in the first octet and all zeros and the remaining three in binary.
04:09
So this is actually how you get your cider notation or slash notation that you may be familiar with
04:15
the cider notation is a quick way of writing sub nets. And in order to determine the slash or the on the cider notation, all you need to do is count the ones in the binary number.
04:28
So in a typical class A I p, your network address would be 10.0 dot zero, allowing you to use the last three octet. It's for your hosts.
04:39
Class of be ranges started the 1 72.16 dot 0.0 address with a sub net mask of slash 16 or in decimal 2 55 down to 55.0 dot zero.
04:55
This gives you a network address of 1 72 16.0 dot zero, giving you the last two AQ tests for host addresses
05:04
and a Class C address, which is probably the most common like, he said, for the home networks starts at 192.168 dot 0.0 with a subject mask of slash 24 or in decimal 2 55.2 55 to 55.0.
05:24
This gives you a network address of 192.168 dot 0.0, giving you just the last octet for host addresses.
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