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In this video, we're going to discuss binary. Binary is a fundamental building block in networks today.

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You need to understand binary if you want to be able to work with networks.

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It's used in multiple places.

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Now, don't worry if you don't know what this means.

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We'll explain it later in the course.

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But just be aware that you need to know binary to work with access lists or access control lists that

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allow you to permit or deny traffic based on an IP address.

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When you configure devices in your network with various IP addresses, you may want to permit one device

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to talk to another device, but then deny a third device from talking to that second device.

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Now, to do that, you permit or deny traffic based on a IP address, whether that's a source IP address

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or a destination IP address.

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You're going to match specific IP addresses based on a binary representation.

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Computers, networking devices and machines use binary.

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That's what they understand.

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We may use English or another language to communicate.

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But machines use binary.

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And for you to implement things like access control lists in a network or something like a subnet mask.

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So determining what a subnet mask is for a specific network, you need to understand binary.

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So make sure that you don't skip this section.

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If you don't know the answer to this question.

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I've seen this printed on many t shirts.

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So if you don't know the answer to this question, then don't skip this section.

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There are only one zero types of people in the world, those that understand binary and those that don't.

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How would you read that?

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Would you read that number as 1 0 as in 10?

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Or would you read it as two if you understand this joke?

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You probably want to skip this video, the section and go to the next section, but make sure that you

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know how to convert IP addresses as in dotted decimal

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IP addresses to binary.

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If you're not sure what I'm talking about, you don't understand this joke.

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Don't worry that 1 0 means two in binary.

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So the joke is there are only two types of people in the world, those that understand binary and those

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that don't.

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If you didn't get the joke.

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Don't worry.

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By the end of this video, you'll understand this joke and understand where the 1 0 comes from.

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Now, as an analogy, to help us understand binary, let's use the analogy of electricity, because

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computers, let's be honest, they have chips in them routers and switches, have specific types of

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chips known as ASICs or Application Specific Integrated Circuits

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It's basically a circuit.

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So computers have circuits and they run on electricity.

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In electricity.

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We either have two states.

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Something is on as in this current or power to the device or it's off.

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So as an analogy, notice that big like there, that's an old antique lamp.

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But I've put a hue bulb in that lamp.

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So that's on.

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That's off no power.

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On those power.

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That's of no power.

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That's on, on means

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current is applied, off means current is removed, so a computer basically only has two states, current

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or no current, on a circuit that

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however, let me turn that back on again.

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That, however, gives us two states.

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So one cable gives us two states.

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So remember this.

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All computers function by using a system of switches that can either be on or off.

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Off equals 0.

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On equals 1 are binary values or either 0 or 1.

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So once again, our analogy.

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That's 1.

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That's 0. 1 0

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I won't bore you too much during that.

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The moral of the story is make sure you understand that binary consists of two states or two values.

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0 1

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That becomes really important now as we scale this analogy.