So, let's dig a little deeper into what the IP address tells us and what are the different portions of the IP address. It's really divided into two parts. The first part is the prefix of the IP address, and the prefix indicates the device's subnet. And a subnet's really a group of devices that are identified by a specific prefix, right? So if you're in a specific subnet it just means that you have a specific prefix. And we denote the prefix with a forward slash. Okay, so in the IP address we would right, for instance, 127 dot 12 dot five dot zero, and we, we don't say the zero. I'll say that why in a minute, but then we say slash 24. 24 would indicate that the first 24 bits, or really, remember there's 8 bits in each of these decimal numbers. So eight, 16, 24, that this is indicating the prefix, right? And so if this was slash 16 it would mean that the the first 16 are indicated in the prefix. And if this was slash eight it would mean that the first eight or just the first number is in the index indicating the prefix. And when we're stating what a prefix is what the prefix is. We typically use the decimal numbers that don't matter and we put them to zero, right? So this one doesn't matter. This one doesn't identify the prefix at all. It's just the first portion of the IP address that does here in this case. And so the, the smaller this number is means that we're using less decimal numbers to indicate what the prefix is. That means that there's more potential for variation in the remaining portion. So the prefix is a smaller number. It means that have, we can have more devices on that prefix. So really with this think a zip code okay, that's really a good analogy to what a prefix is, right? So if you think about a zip code, the zip code tells you if you live at 08024 or something that's going to tell the post office what, what town you're in. Right, so, you're, whatever whatever your prefix is, right someone's trying to address you, or your network device, right? the, the prefix is going to say, okay, what general vicinity, right, that your device is in. And, it doesn't have to be a geographical vicinity. You can think of it like that I, there's, there are things, there's virtual networks as well, and that means you can be living in the same subnet, even if you're nowhere near each other physically. but just, you can think of it just like this just for the time being here. so basically, it'll indicate what general area you're in and that's, that's really your, your subnet, right? And so then all the routing really would probably happen according to the, the prefix at first and then it would get more fine grained. So once the, the mail gets to your town then that mail drivers going to look more specifically and say, okay what street address do I need to go to, then what house address do I need to go to and so on. So this is the main idea here just to show it. This is the, this is the depiction of the internet, right? this is one subnet here, subnet 1. this is another subnet subnet 2. so each of these are slash 24 meaning the first eight I'm sorry, I mean the first 24 bits or the first three decimal numbers are the prefix. This is also slash 24, so the first three decimal numbers are the prefix. slash 24 is common, like in your home for instance, because you don't need a long range of devices. so that's getting us to the next portion, which is the host identifier. So beyond the prefix, right, is the actual host identifier, right? So here in this case, this is slash 24, it means the prefix is the first part. The prefix is the first part, but then the host identifier is the remaining portion, right? So we have a larger range of host identifiers if the prefix is smaller. So as this number gets smaller, it means we can have more hosts within that subnet. Alright, so then, this is another subnet, these are another group of devices showing down here. so, host identifier indicates the host, but within the subnet, right? So, one of these, for instance, this could be dot ten this could be also dot 15. And that wouldn't matter, right, because the, you're not going to subnet two. You're going to subnet one or subnet two, so once you're within the subnet, then you may only look at the last portion. so it comes after the prefixes we set. And this is really, so the prefix is really zip code and host identifier is really then the house address. And it's just a way of thinking about it.
