All right, let's continue on with the wonderful world of network. Plus,
we're moving into module to which is IP. Addressing
I p address scene is a critical element of knowledge that you just have to have going into networking.
So we're going to talk about some of the ideas about the basics of I p addressing and look at it in a similar way to how we look at the Postal Service and discuss what's necessary to get data delivered to your host system.
That includes us looking at ideas like a sub net mask.
We'll also talk about classical add dressing, meaning the I P addresses are grouped together based on a class and what that indicates.
And then we'll talk a little bit about local versus remote. Addressing
will be examining the fact that certain I P addresses are set aside for particular purposes.
We'll need to know what those addresses are and the purpose they serve.
Next, we'll talk about C. I. D. R. Which is classless inter domain routing.
A lot of people will talk about this is submitting, and that's true. We're submitting the networks that we can bring our network into smaller, more manageable pieces.
We'll do that through the I p address ng and getting away from that standard classical system.
And then last but not least, we'll talk about I p Version six and what I p v six has on the horizon for us. But some of the ideas behind it are, and the similarities with i p. So that's what we're going to cover in this section.
So let's jump right in and talk about some I p version for basics.
With IP addressing, this is going to give us a way to send traffic to specific hosts on the network.
This is called the logical address because your I P address is going to change based on your location.
If you remember when we talked about a Mac address, a Mac addresses physically burned into your network. So matter where you go in the universe, your Mac address is going to stay the same. At least that's the theory.
With your I P address, it will contain information on your location so that as you move from location to location, you can still access your traffic or data.
sub net masks are going to be what we use in order to help us determine what traffic is local and what traffic is remote.
When I say local traffic, I mean traffic that's on your network
and traffic that's on someone else's network or a different network is considered to be a remote host.
The thing to remember is, only hosts on the same network can communicate directly.
So if we don't want to have to have a router between us or some other device that will help us get to different networks, if I just want to be able to connect to a host to be a switch or a cross over cable or hub, I'll have to be on the same network as the other host.
If I'm going to connect to a remote location, I need a router of layer three. Switch
to look at a typical I P address I P addresses are 32 bit address is expressed in dotted decimal.
You'll see an example here
Nothing fancy about the address, just a sample.
The important thing to understand is, even though you and I see this I p address and think about in decimal. Remember, it always comes down to binary for our systems.
We're going to have to have a look at conversion of binary in just a few minutes.
Here is the heart and soul of I p address ng.
Think about when you're putting a letter in the mail to someone
when you address the envelope. There is a part of your mailing address whose job it is to get the letter near you specifically to your local post office.
That third line Silver Spring, Maryland
20933 is to get the message near me.
Once the letter gets near me to my local post office, then we need the top two lines to get the letter to me. Specifically,
you can't say that one is more important than the other, right?
We have to be able to locate where Kelly is on the planet to narrow it down. And once we get to that local post office, we need what we call the host ID to get that letter to me.
So we have a network ID and a host ID.
We don't call them that with mailing addresses, but that's the idea behind IP addresses,
there will be a portion that narrows down where you are from anywhere, and then a portion of the address that will get traffic to you specifically
with the mailing address. The city state zip, we said, gets to your local post office.
But when we talk about I p packets the network I d gets the packet to your router. The router closest to you
once the traffic gets on the router closest to you, the host idea is what will be used to get the letter or the packet directly addressed to you.
So the big takeaway I want you to have from this is that I p address scene is very comparable to a mailing address
course with an I P address. It's expressed in dotted decimal. It's a 32 bit address,
but it still has the same elements. At is a portion of the I. P address that gets data near you and a portion that gets data to you.
We look at how all that comes together in the next section