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Just as a mailing address has a specific pattern, reference process, and organizational structure, Subnet Mask does a swell. This segment explains how subnet masks addresses are correctly formatted and demonstrates why that structure cannot be altered. [toggle_content title="Transcript"] Having looked at IPV4 addresses, we usually also have to consider something called the Subnet Mask. When you look at the IPV4 address, there are usually two portions to the IP address; the IPV4 address but only the Subnet Mask allows us know what portions for the network and the portion for the host so if we want to consider an IPV4 address of say 192.168.10.150 this name actually consists of two portions; the network portion of the name and the host portion of the name. The function of the subnet mask is to tell us this. We have 3 classes of subnet masks. We have the class A, class B and class C. The class A is denoted as 255.0.0.0. The class B is denoted as 255.255.0.0. The class C is denoted as 255.255.255.0. When we look at these Subnet Masks bear in mind, we can never have it like this; 255.0.255.255. You will never have the 0 before a 255. You will only have it in this fashion, 255.255.255.255.255.255 so everywhere we have the 255 that constitutes the network portion of the address. Everywhere we have 255 and everywhere we have the 0 that is I will give as a wavy sign, the host ID, the host ID, the host ID. So if we were to say that this IP address has a Subnet Mask of 255.255.255.0 effectively that makes it a class C and we can see that this portion would constitute the network ID and the 0 portion will constitute the Host ID. So if we were to say what is the network ID for this IP address, our address would read 192.168.10.0 and if we were to say what is the host ID of this IP address we will say it is 0.0.0.150. [/toggle_content]
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