-: So in this section of the course, 2 2
we've talked a lot about virtualization in the cloud. 3 3
And you may be wondering, 4 4
why do I really care here in Network+? 5 5
Because as a network technician, 6 6
we're not really going to be doing 7 7
a lot of cloud or virtualization, right? 8 8
Well, that's true, but there is some things 9 9
you just want to be comfortable with 10 10
because we keep moving more and more into virtualization 11 11
and more and more into the cloud. 12 12
So, in this lesson, I want to show you a tool called GNS3. 13 13
Now, this tool is a virtualized networking environment 14 14
and it allows you to connect different virtual machines 15 15
or even physical machines together using this tool. 16 16
Now, you don't need to be an expert on this tool. 17 17
I'm just showing you that the tool exists 18 18
and some of the things you can do with the tool. 19 19
For the Network+ Exam, no one is going to ask you about GNS3. 20 20
It's not on the objectives. 21 21
This is just for you to get a little bit of experience 22 22
to see how it works, 23 23
and if it interests you, you can go to gns3.com, 24 24
download the tool for free, 25 25
and start playing with it and using their tutorials. 26 26
So, let's jump onto the computer and take a look at GNS3. 27 27
All right, so here we are inside of GNS3. 28 28
Now, you'll notice at the center of my screen is a router. 29 29
This is actually a VyOS router, 30 30
and I can go in and configure this router 31 31
as if it was a physical device. 32 32
Everything you see here on my screen right now 33 33
are virtual devices. 34 34
Over on the left side of the screen, 35 35
I have Firefox, Kali Linux, and a Network Defense Appliance. 36 36
All of those are virtual machines that exist within GNS3. 37 37
They're just a piece of software. 38 38
Then, I have these switches, 39 39
the Network Outside and the DMZ Switch. 40 40
Both of those are virtual devices 41 41
that are emulating a real piece of hardware 42 42
that would normally be something that would cost you 43 43
hundreds or thousands of dollars. 44 44
And here in GNS3, you get to use them for free. 45 45
The same thing with the router here in the center. 46 46
It's connecting my two networks, 47 47
my Outside Network and my DMZ. 48 48
And then in my DMZ, I have a Snort machine, 49 49
a LAMP, which is a web server, 50 50
Metasploitable2, which has a web server, an SSH server. 51 51
It has an FTP server, a Send Mail server, 52 52
and all sorts of other stuff, 53 53
and then DVWA, which, again, 54 54
is another vulnerable web application. 55 55
This particular lab is one I use in my PenTest+ course. 56 56
But I just want to pull it up here to show you how it works. 57 57
So, what I'm going to do is show you 58 58
that we can actually go into this router 59 59
and we can run configurations on it, 60 60
just as if we were doing it on a real piece of hardware. 61 61
The great thing about this 62 62
is if you really want to get in depth 63 63
and practice your on-the-job skills, 64 64
you can download GNS3, load up some routers, 65 65
connect them together, and make your own virtual network. 66 66
To access the router, 67 67
you just right-click on it and go to Console. 68 68
This will launch the Console, 69 69
which is a terminal for you to configure the router. 70 70
So, here we are at the prompt, 71 71
and it's going to say Welcome to VyOs, 72 72
which is the operating system that runs this virtual router. 73 73
For me to be able to use it, I need to log in, 74 74
and the default is vyos, and the password is vyos. 75 75
Now, once I'm logged in, 76 76
I can run any command that this router supports. 77 77
The first one I want to run 78 78
is actually called show configuration. 79 79
And if I do show configuration, 80 80
you're going to be able to see 81 81
the configuration of this router. 82 82
Currently, there are three interfaces or plugs 83 83
that would be plugged into this router or Ethernet cords, 84 84
and those are eth0, eth1, and eth2. 85 85
eth0 is my Outside Network, 86 86
so this has the address of 10.1.1.1. 87 87
So, if I go back to my diagram, 88 88
you can see my Outside Network is here. 89 89
So, that address, 10.1.1.1, 90 90
is this Ethernet, Ethernet Zero, 91 91
that's connected on this side of the router. 92 92
Now, if I want to figure out what's on this side 93 93
of the router, I'm looking for the DMZ Switch. 94 94
And you can see that is right here. 95 95
That is 10.10.10.1. 96 96
That's its IP address. 97 97
And then, we have eth2, which will be its connection 98 98
to the outside world, which is currently off, 99 99
but it would be 172.16.10.1, 100 100
and that would be another connection 101 101
that would come out here, 102 102
connecting us to a modem or a switch 103 103
or something that would give us connectivity 104 104
out to the Internet. 105 105
Right now, I have this set up, 106 106
so this all works in a Local Area Network with two networks, 107 107
my left-side network and my right-side network, 108 108
which is my Outside and my DMZ. 109 109
Now, we used nmap earlier with Kali 110 110
so I'm going to use that again, 111 111
and we're going to go ahead and take a look 112 112
at this particular machine called the LAMP Server. 113 113
The IP address for this is 10.10.10.10, 114 114
and that comes off of this switch, 115 115
which was the 10.10.10.1. 116 116
And so, when I go over to Kali, 117 117
I'm going to be able to log into that Kali machine, 118 118
and we're just going to use nmap 10.10.10.10. 119 119
Now, I assume this is a web server 120 120
because it was called a LAMP Server, 121 121
which stands for Linux, Apache, MySQL, and PHP, 122 122
which are four core technologies to run a web server. 123 123
When I run that nmap scan, 124 124
it comes back with three ports that are open. 125 125
We have Port 22, which is ssh, 126 126
which allows me to have a connection 127 127
through the Console like you see here on Linux. 128 128
You have Port 80, which is http, 129 129
which is the web browser that we'd be loading that website. 130 130
And we have Port 880, which is a web proxy. 131 131
Again, these are ports that should look familiar to you. 132 132
Now, what this proves 133 133
is that I have all of these virtual machines 134 134
and they are networked together properly. 135 135
Because I was able to send a command from Kali 136 136
through this switch, through this router, 137 137
through this switch, and all the way up to the LAMP Server 138 138
to say what ports are you running, 139 139
and then bringing that all the way back 140 140
over to the Kali machine. 141 141
We can do the same thing 142 142
over to this Metasploitable2 machine, 143 143
which is 10.10.10.11. 144 144
So, I'm just going to do nmap 10.10.10.11, 145 145
and you'll see the exact same thing happen. 146 146
We went out, we pulled all of those ports and said 147 147
which ones are open, tell me about them, 148 148
and then, they give that information back to Kali. 149 149
So, this is just a very simple demonstration 150 150
of what you can do inside the GNS3. 151 151
The point of this lesson 152 152
isn't to make you an expert in GNS3. 153 153
In fact, I didn't teach you how to install it 154 154
or even how to operate it, really. 155 155
I just want to show you the fact 156 156
that you can have one machine made up of software. 157 157
All of these was running inside of my own work station. 158 158
There were seven different machines, 159 159
two different switches, and a router, 160 160
and all of them were just a series of ones and zeros. 161 161
It was no cost to set up 162 162
because there's no physical hardware. 163 163
It's all virtualized. 164 164
We could take this same lab and I could put it up on AWS. 165 165
And if I did that, it would be in the cloud 166 166
and I can operate it from there. 167 167
This is the idea with virtualization. 168 168
It's bringing the costs down 169 169
and increasing our capabilities. 170 170
I hope this got you a little bit interested in GNS3. 171 171
If you have some time, 172 172
I recommend downloading it and playing it. 173 173
It's really interesting, 174 174
the things you can do inside of GNS3.