Instructor: Virtualization. 2 2
In this lesson, we're going to talk a little bit 3 3
about virtualization. 4 4
Now, I'm not going to go and rehash everything you learned 5 5
in A+ or Security+ about virtualization. 6 6
I assume you already remember that, 7 7
but I'm going to cover some of the highlights 8 8
and then we're going to talk about two specific 9 9
types of virtualization. 10 10
First, what is virtualization? 11 11
This is a review. 12 12
Virtualization is a host computer that's installed 13 13
with a hypervisor that can be used to install 14 14
and manage multiple guest operating systems 15 15
or virtual machines known as VMs. 16 16
Now, what does this look like? 17 17
Essentially, you have a piece 18 18
of hardware that's called the bare bones 19 19
and then you install some sort of virtualization on it. 20 20
That would be called a hypervisor. 21 21
Now that hypervisor can be either a bare bones hypervisor 22 22
or it can be an operating system 23 23
with a hypervisor running on top of the operating system. 24 24
For instance, on my laptop, I have a MacBook. 25 25
On that MacBook, I have the Mac operating system. 26 26
And on that Mac operating system, I have a hypervisor 27 27
known as VMware that I can actually run Windows inside 28 28
of that as a virtual machine. 29 29
Now, as part of that hypervisor virtualization, 30 30
I can then install the guest operating system 31 31
shown here in yellow, 32 32
and then any applications I want. 33 33
So on my particular system, 34 34
even though I'm running a Mac system, 35 35
I have one virtual machine 36 36
with an operating system that's Windows 10 37 37
and another one that's running a Ubuntu Linux. 38 38
And that way I have access 39 39
to all three operating systems 40 40
for whichever programs I need 41 41
or whatever demonstrations I'm trying to do for my students. 42 42
Now when we talk about virtualization in this lesson, 43 43
we're going to focus on two main areas. 44 44
We're going to talk about VDI, 45 45
which is virtual desktop infrastructure 46 46
and we're going to talk about containerization 47 47
and how both of these affect you as a security analyst. 48 48
When we talk about VDI, 49 49
this is a virtual desktop infrastructure. 50 50
This is a virtualization implementation 51 51
that separates the personal computing environment 52 52
from a user's physical computer. 53 53
So I have a Windows 10 machine that I can access 54 54
and it's actually part of a VDI network. 55 55
So when I want to use it, I will log into a piece 56 56
of software on my Mac, it will reach out to the cloud 57 57
and I will connect to that Windows 10 machine. 58 58
And then I have control over that virtual image 59 59
that's in the cloud being run. 60 60
They have all the operating system, the applications, 61 61
and everything I need, and every time I try 62 62
to run a command, it processes it on that cloud server. 63 63
It doesn't process it on my local machine. 64 64
My local machine is just a dummy box to connect to it 65 65
and that's the idea of VDI. 66 66
So as you can see, you can have VDI 67 67
on lots of different things. 68 68
You can have it on a desktop, a laptop, a phone, a tablet. 69 69
It doesn't really matter because the device 70 70
is just there to connect to the server 71 71
and then run that virtual image, 72 72
which is being processed 73 73
all that data on the server. 74 74
Now again, as I've been saying, 75 75
the server is going to perform all 76 76
the application processing and the data storage 77 77
so you can use a Chromebook, a MacBook, a Windows machine, 78 78
it doesn't matter because whatever that VDI 79 79
environment is, that's what you're actually connecting to 80 80
and that's what's actually processing 81 81
the application for you. 82 82
Now, a lot of companies can completely offload 83 83
their entire IT infrastructure by using third-party 84 84
services by using this VDI concept. 85 85
And so it's a really tempting thing for CIOs to do, 86 86
because I don't have to run 87 87
the operating systems anymore. 88 88
I don't have to worry about patching them, 89 89
because my third-party provider can do it all for me. 90 90
That's one of the big benefits 91 91
of VDI and one of the main selling features. 92 92
Now, one of the bad things about it though, 93 93
the big disadvantage of VDI is that users 94 94
have no local processing ability. 95 95
So if the server is down or the network is down 96 96
or the connectivity is down, you can't do any work. 97 97
And so if there's an outage on that server, 98 98
everyone's down. 99 99
Whereas right now, I'm sitting on my laptop 100 100
and if my internet connection went out, 101 101
I could still do work. 102 102
But in VDI I couldn't because if my network connection 103 103
is down, I can't reach the server. 104 104
So these are the things you have to think about. 105 105
Now, the next area we're going to talk 106 106
about is containerization, and this is much more focused 107 107
on servers instead of the end user. 108 108
When we talk about VDI, 109 109
it's really focused on your end users, right? 110 110
When we talk about containerization 111 111
this is a type of virtualization that's applied 112 112
by a host operating system to provision 113 113
an isolated execution environment for an application. 114 114
And a lot of people use these 115 115
because they're fairly secure. 116 116
The nice thing about doing containers 117 117
is that containers will enforce resource separation 118 118
at the operating system level. 119 119
So what this really looks like 120 120
is you have a piece of hardware, 121 121
and then on top of that hardware, 122 122
you have some host OS, 123 123
and then you have a container manager, 124 124
something like Kubernetes or Docker 125 125
or something like that. 126 126
And then it has these different containers 127 127
that can be created. 128 128
In this case, I have three containers. 129 129
I have the first environment, 130 130
which is based on the kernel of the host OS. 131 131
So this is a Linux system, and so in this case, 132 132
container one is running Linux 133 133
and it can run some applications there. 134 134
Now, container two can do the same thing. 135 135
Container three can do the same thing. 136 136
Because we're all sharing the same host operating system, 137 137
this takes a lot less resources 138 138
than doing pure virtualization using virtual machines, 139 139
because each virtual machine needs 140 140
its own operating system, 141 141
which could be eight or 10 gigabytes each. 142 142
Here we're all sharing the same operating system 143 143
so it uses a lot less storage 144 144
and a lot less processing power. 145 145
This is the real benefit 146 146
of using something like a container. 147 147
Now, because these containers are logically isolated, 148 148
they can't actually interface with each other. 149 149
If I wanted those two containers to talk, 150 150
I actually would have to connect them 151 151
through a virtual network and do the right routing 152 152
and switching to allow them to talk. 153 153
Because by default, 154 154
they have no way of talking to each other. 155 155
That's a great thing for security, 156 156
but here's your big warning 157 157
when you're dealing with containers. 158 158
If an attacker compromises that host OS 159 159
underneath that Linux operating system, 160 160
for instance, guess what? 161 161
That means they have access 162 162
to all the containers as well. 163 163
And so this is one of the big vulnerabilities. 164 164
I can have a container system that's running 165 165
50 different servers right now 166 166
because I'm running all these different servers 167 167
and services using containers, 168 168
but if somebody gets that one server that's underneath, 169 169
they now have access to all 50. 170 170
This is the things you have to weigh 171 171
when you start figuring out, am I going to virtualize? 172 172
Am I going to use VDI? 173 173
Am I going to use containers? 174 174
What is the risk versus reward? 175 175
There's a balancing act here. 176 176
It's a business decision 177 177
and it's a cybersecurity decision 178 178
and so you have to measure these things 179 179
to decide what is the best thing for you.