Subtitles of the Movie

Now let's talk a little bit more about the IP version 4 Address. Now in a different video that was entitled TCP IP Basics we just kind of covered some very basic information about TCP IP and I did a little diagram about hooking a few computers together in a small network. Now let's dig into that IP version 4 Address. Now if you remember from that we used an address there called 192.168.2.1 OK, now there's a bunch of things to notice about this address. First of all it is divided into four pieces and these are called Octets, OK? O-C-T-E-T-S, Octets. The reason it's called octets is because we are really looking at a number that we're using four sets of 8 bit binary to represent these numbers. Now that sounds confusing but let me just show you a picture. If we convert 192 into binary that's what it'll look like, OK; 168 is another section of binary, 2 is another one, 1 is another one. Now if you've never seen binary before hang with me here, OK? And just go through this. With binary what we're looking at here, this is an octet, these 8; this is another octet, this is another one and of course, this is another one. So if you've got four sets of 8 bits then you have 32 bits and so this address is a 32-bit IP Address, OK? Now, binary basically means on or off and so the zero means this position is off and the ones mean this position is on. Now, we assign a value based on the position that's turned On and turned Off. Now, as humans we're used to reading things in this decimal notation, 192, very easy for us to use and add and so forth. Well, this is what's happening in the background with your computer and just step through this with me here, OK? The first position is equal to 1, the second position and binary is equal to 2, the third position is equal to 4, the fourth is equal to 8 and now you see a pattern - these are simply doubling as they go to the left - 16, 32, 64, 128. And notice these last two are red. We are representing 192 with this 8 bit decimal notation and the last two, 164 and 128 were turned On. Well, notice what happens. If we add 128 to 64 we get 192. OK? So, to show 192 in decimal form, that's easy, a 1 a 9 and a 2. To show it in binary form it's 11 followed by six zeros, OK? Now, obviously we can represent any number from zero, by turning them all off, up to 256. If we turn all of these on and add all these numbers up we get 256, OK? Now, you can get some help with the Windows calculator here, so let me go out and grab the Windows calculator and show you some things that you can do with it. OK, so you've noticed I've opened the Windows calculator, just Start, Programs, Accessories, or Start, Accessories, depending on the Operating System you're using, but just open the Windows calculator, it's easy to find and if you click on View yours is probably going to look like this. If you click on View and go to Scientific, they have a really cool tool here. First of all, let's convert 192 into binary using this, so we're on decimal, so we just type 192 then we click on binary and notice there's a 11, two zeros and then four more zeros, exactly what we've got here. This just means that if we start from this right side, right here, OK, this is 1, the next one's 2, then 4, then 8, then 16, then 32, then 64, then 128. We add the last two, right, 64 and 128 and we get 192. Let's do some different ones. Let's say, clear that - I keep trying to highlight it for some reason - let's do 37, so we put it in binary and if you add all those up and notice it's not showing us leading numbers out here so the first one is a 1, the second one zero, the third one is a 1 which is a 4 so those two together are 5 and then that is, that's going to be the 8, the 16, the 32 and so the 32 is turned On, so the 32 plus the other 5 equals 37. Now notice it's very easy to switch from decimal to binary here, OK, because notice I can also go back the other way. OK, so I can type in the binary and switch back to decimal and it will show me. OK, so that's the Windows calculator. That's very easy to use to help you out a little bit here. Now, there's a little bit more going on here that we're going to get into in the next video which is some tricks that we can do. Since the computer's looking at it in binary we can also do network addressing here along with host addressing and with that I want you to think just like the address at your house, you have a street address that everybody on your street shares but then you have an individual house address that makes your house unique on that street and that is exactly what IP version 4 addresses can do and so we will look at that in the next video, but for now I want you to get your head wrapped around binary because in the upcoming next two or three videos we're going to talk about binary and all kinds of tricks for reading and figuring out some binary numbers and so forth, OK? So, I'll look for you in the subnetting Basics video after this.