There's a lot of pretty basic questions on the exam that cover information that well, in my opinion, if you're at this level of study, you should know everything I'm about to talk about, but for completeness, and because they are listed as objectives, let's go ahead and go through these. First of all, what I want to talk about is IP addressing. Now, there are two different types of IP addressing they're being used today. There's the old school ipv4 and here's an example of ipv4. You'll notice that we have four octets, separated by three dots. Each of these octets is actually eight binary values.
So there are four of these. So four times eight. This is a 32 bit address. ipv4 has been around for a long, long time, and it looks to be around for a little bit longer, however, other stuff is coming. Now, when we talk about ipv4 addresses, there are certain addresses that you need to be able to recognize instantaneously and these are known as the private IP addresses. If you're going to put a computer on the internet, you're going to have to have a legitimate public IP address handed to you indirectly from ima.
So usually what happens our local ISP gives us those addresses. However, if you have a private local area network and everybody's just using web browsers and such, it's common for us to separate this router from the real internet through what's known as natural address translation, or Nat. And what we're going to do is then we're going to use private IP addresses. So you need to recognize private IP address ranges. So let's go ahead and knock them all out. First, any IP address that starts with the number 10 is a private IP address.
Second, any IP address that goes from 172 16 to 172 31 is a private IP address. And third, anything that starts with 192 168 the third value is up to you but there has to be a third value. In this case, these are also private IP addresses that I hope you record Nice these. Okay, that's pretty much all I want to cover for ipv4. ipv6 has been around for a number of years, but it's only in the last few years that it started to become common. If you run an IP config on your system, check the IP address, you'll see that you might find an address that looks something like this.
And ipv6 address is broken up into eight of these four digit chunks. And notice some letters are used here because this is hexadecimal as well. So if you take a look at this entire address, it actually goes up to 128 bits. So an ipv6 addresses much bigger than an ipv4 address. Now, if you were to look on your system, you'll notice that you often have two or more ipv6 addresses. First, you're going to have your link local link.
Locals are easy to identify because they always start with F eight zero link locals are generated automatically by individual hosts. Then you're going to have some type of internet Address, they often will have numbers that start in the 2000s range. So here's an example of an internet ipv6 address. So it's very common within the ipv6 world to have more than one IP address where with ipv4, you're only going to have one address. Alright, so make sure you're comfortable with ipv4 versus ipv6. Now, the next thing I want to talk about is when we talk about when we use the word TCP IP, that's really kind of a lie.
Because really what we're talking about is we have a number of transport protocols. We have TCP, we have UDP, and we have ICMP. So let's take a moment and talk about these three. First of all, TCP. TCP does most of the work on the internet and that's why we call it TCP over IP and not TCP and UDP and ICMP over IP. TCP is a connection oriented type of protocol.
In a TCP what will happen I'll have two ends of a connection. So once a client wins a server What will happen is the client will first send a Hello message, then the server will send back. Yes, I got it. And then the client will again send his message. And that what we call the three way handshake is the cornerstone of TCP. Now, TCP has some really, really important aspects to it.
Number one, it's connection oriented, we always have to start with this connection. And number two, you can have lots and lots and lots of packets being sent. And that's why you will see for things like web pages, and for email and stuff like that, pretty much everybody uses TCP but there are two other protocols. The next one is called UDP. Now UDP is a lot different than TCP number one, UDP is connectionless. So if I've got a client, and I've got a server, somebody just sends a message in hopes that the other person gets it so there's no acknowledgement to it.
The other thing about UDP those you can send lots and lots of packets. So UDP is used in situations where you have Have a high degree of confidence that the other person is listening. The last one is ICMP. ICMP doesn't really run at the same level as TCP and UDP but it kind of lives in the same world. So we tend to put it there. So ICMP is like the maintenance worker of TCP IP networks.
ICMP his main job is to handle the little important but boring things. For example, ARP messages and pings and all that stuff. Run under ICMP, ICMP is always going to have just one packet doing whatever it's going to do. And that's pretty much all there is to it. Alright, so for the exam, make sure you know ipv4, ipv6, TCP, UDP and ICMP