Table of Contents
Today we are going to talk about IP addresses specifically about Public IP addresses and Private IP addresses and we will go to Subnet Masks later.
So first of all let’s talk about Public and Private IP’s and let me kind of explain how this works!
A Public IP address is an IP address that you will find on the internet. Now the word on the internet or words on the internet is really important because what’s something on the internet that means directly connected to the internet when you are on the internet you must have a Public IP address which means that IP address is unique all over the world.
No two people have this same IP address anywhere in the world like they have to be unique. Same is with the phone numbers analogy. So the number must be a unique number and we call that a Public number because Public means it’s Public, everybody can see it. It is for everybody. Everybody knows it; everybody knows what that number is.
It’s a Public number on the opposite side of that is called Private IP address and a Private IP address is exactly opposite of Public IP address. The Private IP address is not on the internet. It cannot be on the internet because they are set aside for a specific use to work in what’s called a private network. Which could be like a home network or corporate network?
So they are not on the internet. Now the reason behind is why you have this is again forgive me for another small history lesson here, but this really explain it quiet well.
We as individuals were never meant to be on the internet because the internet was designed in the way IP addresses where designed.
They were designed to be for schools, governments and businesses. It was never designed for individuals. So in 1992 that’s when the internet we know it today was actually created. It was opened up to public and then we as individuals were able to get on the internet. Well! The problem is that with the way the IP addresses work in a way like an IP address version 4 works there are only so many addresses to go around and again if you have to have a unique IP address all over the world, which everywhere else in the world they have to have a unique IP address as well.
So we were quickly running out of IP addresses as individuals were getting on the internet. So what happened is they set aside some IP addresses and they said you know what we are going to call them as Private numbers and those private numbers were used by the network administrators will be able to use these numbers in any way they see it fits.
They can assign them however they want. They can use them however they want to use them. They don’t need to ask for permission. They don’t need to ask for pay-for nothing! But the tradeoff is that these private IP addresses on the internet they must use a Public address. So what happened was is that they set aside these numbers and that allowed us to actually extend or expand the use of IP addressing by being able to use Private IP addresses in our businesses or home and then they translate those to a public IP address when you are trying to get on the internet and this is how these networks actually work; today and what I want to explain you is very important this would be on certification.
This is all about various certifications even a little bit in Microsoft. This information that I am going to tell you now is actually on the certification tips so this is very important stuff that you really need to know about IP addresses.
So you already know these ranges of these IP’s: Class A, Class B, and Class C.
You already know what it makes those. So what I am going to tell you is the Private ranges. What IP addresses have been set aside for the private use?
I can tell you that there is a range in Class A, Class B, and Class C. One ranges in each. So what this about you to do is that it allows you if you are a member of Class A are the large networks, the Class B is for medium networks and Class C is for small networks.
This allows you to use the one that is unique. If you need something small, go with Class C. If you need some really large then go with Class A. The beautiful thing is that the IP addresses about which I am going to tell you that you don’ have to ask for permissions, you just use them as you see it fit. It’s wonderful!
So in the Class A anything that starts with number 10 is a Private address. So 10.0.0.0 all the way to 10.255.255.255 and everything in between is Private. So in another words, if you have ever seen an IP address that starts with 10 it’s a private address. For the Class B here actually the range of IP addresses is 126.96.36.199 all the way to 172.31.255.255 and everything in between 172.70, 172.80 and so on all the way to 172.31, anything in this range is a private address. Again not on the internet.
With Class C the range is 192.168.0.0 all the way to 192.168.255.255 and everything in between 192.168.1, 192.168.2,…… and so on and so on anything in there is Private not on the internet.
So if you ever come across one of these IP addresses you are not on the internet. Now you might be thinking about yourself, wait a minute! Yes I am! I can get on Facebook, I can get on Google, I can look up my emails, what you have there is a technicality, but it is different.
You have “Internet Access”, which means that some were on the network is a router that the router device that connects two different networks together so somewhere in the network is your router that is connecting your private network to a Public network that goes on the internet. So you are not full on the internet buy you have internet access.
Again a small technicality but the technology all the same and you can view people on that too and you can ask “hey! You are on the internet”. They have one of these IP addresses they are not on the internet. They might have internet access but they are not on the internet though people lookout for that.
Keep these numbers in mind, because these numbers are very important. I am telling you they would be in your certification tests. Pretty much it got the network technicalities so they are really important. So this is your Private IPs not on the internet which means the all the other IP addresses besides these IP addresses are on the internet which we call them “Public”.
Now let me talk a little bit about Subnet Masks:
What a Subnet Mask is? What it means? Why you have it? What are the purpose and all that? I am going to tell you about that.
OK! So let’s say we have an IP address as 192.168.1.1. We know that it belongs to Class C IP addresses that I just told you about. Now when someone gives you an IP address, if they don’t give you the subnet mask they are really giving you only half information that you need. You can’t do much anything else with this along with it you must have a subnet mask which is going with it.
Because in reality they work as a pair. They need to be put in together and one really can’t work without the other. So if there is no subnet mask you really can’t tell me all about this IP address so I am telling you the subnet mask is 255.255.255.0 which is standard-class subnet mask. Now I can reveal the whole story, giving you all the information you need.
Now again what is it mean? Well! The whole point of the subnet mask is to identify the numbers above it into which numbers we are going to present on the network and which numbers we are presenting on a node. Wherever you see the 255.255.255.0 the numbers above that means that number is the part of the network because remember in a subnet mask 1’s represents networks and when I say I remember you have to know who the number belongs to binary.
Computers and everything really only understands binaries. So when I convert this to binary to 1’s, 8 1’s, 8 1’sto 8 0’s wherever you see the 1’s in the subnet mask that number above that means it’s a part of the network and the subnet mask is actually tells all network devices- network cards, routers, etc. That tells them that the numbers above tells the network and the last number represents the node or the host and that’s it! That’s what the subnet mask does.
Now when we talk about standard subnet masks i.e. when you have Class A, Class B, and Class C IP address their subnet masks also goes along with those IP addresses as you in our example we called it a standard class subnet mask. It goes right with the Class C that’s inspirational.
Class B – 255.255.0.0
Class C – 255.0.0.0
And if you think about it these numbers here 255’s and 0’s they correspond perfectly with the class. The 255 in Class A represents the network and last 3 0’s represents the nodes.
Class B – the first 2 represents the network and last 2 represents the node and in Class C the first 3 have the network and the last one has the node.
This is all about Private IP address, Public IP address and the subnet masks. I think you must find it helpful. Thank you for reading my blog, if you have any suggestions regarding this topic you can leave a comment below in the comment section.
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