Rules of IP addressing - Windows Server Tutorial

- [Man] Now, there are some rules that you need to understand when it comes to working with IP addresses. So, let's go over them real quick here. First thing you need to understand is that each of the four numbers in an IP address, right, when we see a typical IP address, Each of those individual four numbers that make up the IP address is called an octet. And the reason why it's called an octet, is 'cause you have to remember that when working with an IP address with IP version four, it's a 32-bit address, and if we're going to divide that into four numbers, well then that means each one is going to be, well, 32 divided by four is eight. And so eight bits would be an octet. Now, why is this important to know? Well, this is important to know, because in binary, each bit can be a one or can be a zero. And so what that leads to, is it leads to understanding that each number, you know, in the octet, can only be from zero to 255. in the octet, can only be from zero to 255. And the reason why, is because if you took eight zeroes, And the reason why, is because if you took eight zeroes, which is the smallest binary number you can have, eight zeroes equals zero. And if you took eight ones, and you did the math, and you converted it to decimal, and by the way, I have another video on how to do that conversion if you aren't familiar with it, in an IP address can only be between zero and 255. Now, another thing you need to know is that the first octet cannot be 127. that the first octet cannot be 127. And the reason why is because that entire range of IP addresses have been reserved for diagnostics. And even though the whole range has been reserved, it's kind of funny because, really, there's primarily only one that we see used very often. And that would be 127.0.0.1, which is commonly known as a loopback address, which is commonly known as a loopback address, or sometimes is also referred to as pointing to the localhost. Meaning, you're pointing back to yourself. And it has to do with diagnostics and troubleshooting. Now, another rule that's very important to know, is that a host ID cannot be all zeroes or 255s, right? is that a host ID cannot be all zeroes or 255s, right? So, if you think of the breakdown the network ID for the network you're on. And, all 255s, within that network, And, all 255s, within that network, represents what's called a broadcast address. So, if you ever have a transmission that needs to be a broadcast, that's saying, The way you do that is by sending it to whatever the network ID is, and then followed by all 255s. So, an example would be if we took our, you know, 192.268.10.101 IP address that we had a moment ago, 192.268.10.101 IP address that we had a moment ago, and we assume that we have a subnet mask of 255.255.255.0, and we assume that we have a subnet mask of 255.255.255.0, what we're saying is that 192.168.10.0, is the network ID. what we're saying is that 192.168.10.0, is the network ID. what we're saying is that 192.168.10.0, is the network ID. what we're saying is that 192.168.10.0, is the network ID. That represents that network. No host can actually have zero on that network. No host can actually have zero on that network. And therefore, on that network 192.168.10.255 And therefore, on that network 192.168.10.255 And therefore, on that network 192.168.10.255 And therefore, on that network 192.168.10.255 would be the broadcast address on that network would be the broadcast address on that network would be the broadcast address on that network would be the broadcast address on that network to communicate with everybody. to communicate with everybody. Alright, so these are some of the rules Alright, so these are some of the rules that you need to follow when it comes to IP addressing. that you need to follow when it comes to IP addressing.