-: Wireless Networks or WLANs. 2 2
In this section of the course, 3 3
we're going to cover wireless networks. 4 4
Now wireless networks are great 5 5
because they extend your physical network 6 6
into the wireless domain. 7 7
It can allow your users to run wherever they want 8 8
inside of a given coverage area. 9 9
If you think about a college, for instance, 10 10
you might have an entire campus, 11 11
including numerous buildings, 12 12
the outdoor spaces, 13 13
and everywhere covered by this wireless network. 14 14
You can just take your laptop, 15 15
open it up at a picnic table 16 16
and gain access to the world. 17 17
Now, the popularity of wireless networks keeps increasing 18 18
over and over and over again. 19 19
Back in the late 1990s, 20 20
there were just a few places that had wireless networks. 21 21
Nowadays, though, we expect wireless networks 22 22
pretty much everywhere we go. 23 23
Heck, we even have them in airplanes 24 24
as we fly across the globe. 25 25
Anytime you go to a coffee shop or a restaurant, 26 26
you can usually expect to be able to pull out your phone 27 27
and find a wireless network. 28 28
They're very convenient to use, 29 29
and they expand your network throughout an entire room, 30 30
a floor, a building, 31 31
or an outdoor space using this wireless technology. 32 32
Wireless networks are definitely here to stay. 33 33
So in this section of the course, 34 34
we're going to be focusing on domains two, four and five, 35 35
specifically objectives 2.1, 2.4, 36 36
4.2, 4.3 and 5.4. 37 37
Objective 2.1 states that you must compare and contrast 38 38
various devices, their features 39 39
and their appropriate placement on the network. 40 40
Objective 2.4 states that given a scenario, 41 41
you should be able to install 42 42
and configure the appropriate wireless standards 43 43
and technologies. 44 44
Objective 4.2 states that you must compare 45 45
and contrast common types of attacks. 46 46
Objective 4.3 states that given a scenario, 47 47
you must apply network hardening techniques. 48 48
And objective 5.4 states that given a scenario, 49 49
you must be able to troubleshoot 50 50
common wireless connectivity issues. 51 51
All right, that is a lot of different objectives, 52 52
but really in this section, 53 53
we're going to cover the fundamentals of wireless networks, 54 54
how they're configured, 55 55
how to use the different frequencies and antennas 56 56
and how to best secure them. 57 57
When we look at wireless networks, 58 58
the most common type 59 59
is what we refer to as 802.11 or WiFi. 60 60
Now I want you to write that down in your notes. 61 61
When you see 802.11, 62 62
this is the standard for wireless networking, 63 63
known as WiFi. 64 64
There are several standards underneath that, 65 65
and we're going to talk about them in this section. 66 66
This includes 802.11a, b, 67 67
g, n, ac and ax, 68 68
but we're going to get into those 69 69
in a separate video. 70 70
There are also other wireless options out there 71 71
that you may find in use. 72 72
Most of those are going to be used 73 73
for Personal Area Networks, 74 74
things like Bluetooth, Infrared, 75 75
Near-field communications, 76 76
Ant+, and Z-Wave. 77 77
On the other hand, 78 78
we also have some wireless options that exist for us to use 79 79
in Wide Area Network connections, 80 80
things like Cellular and Microwave, 81 81
Satellite and High-frequency radio networks. 82 82
But if you're dealing with a Local Area Network, 83 83
you're almost always going to be using WiFi, 84 84
which consists of those 802.11 standards. 85 85
Now, when you're dealing with wireless networks, 86 86
there are really two ways you can do it. 87 87
You can operate in what's known as Ad-Hoc mode 88 88
or Infrastructure mode. 89 89
With Ad-Hoc mode, each wireless device 90 90
is going to communicate directly with the other, 91 91
without the need of a centralized access point. 92 92
This is very much like a peer to peer connection 93 93
where two devices don't need to rely on a centralized switch 94 94
or server to communicate. 95 95
Now, Ad-Hoc mode works great 96 96
if you're doing something simple like gaming 97 97
or doing a simple file transfer. 98 98
But if you want to be able to connect to 99 99
and be able to get out onto the internet, 100 100
you're probably going to need to use something 101 101
better than Ad-Hoc. 102 102
And that is why most people use Infrastructure mode. 103 103
Now Infrastructure mode is when you communicate 104 104
through a centralized access point or router, 105 105
and it's going to look a lot 106 106
like a star topology, essentially. 107 107
All of your devices 108 108
are going to connect back to the access point, 109 109
and then from there they gain access to your network 110 110
or the internet. 111 111
This is the traditional WiFi 112 112
that you're probably used to in a coffee shop, 113 113
your home or your office, 114 114
because everything's going back into this infrastructure 115 115
where you have other network infrastructure 116 116
like routers and switches and firewalls 117 117
that support it 118 118
and help get your traffic out to the right place. 119 119
Now, when you're using Infrastructure mode, 120 120
you have to have some kind of a device 121 121
to bring all those wireless devices 122 122
and connect them to your physically wired network. 123 123
This is where the concept of a WAP 124 124
or Wireless Access Point comes into play. 125 125
Now, this is commonly referred to as a WAP, 126 126
like I said, 127 127
or you might hear it abbreviated as an AP 128 128
or Access Point. 129 129
These devices are used to extend your wired network 130 130
into the wireless domain. 131 131
Now a Wireless Access Point 132 132
is not going to interconnect different networks though, 133 133
because it's not considered a router. 134 134
Everything that connects to that Wireless Access Point 135 135
is going to be treated as if it was connected to a hub 136 136
using copper cables. 137 137
Essentially, this means that all your wireless devices 138 138
are going to be in the same collision domain 139 139
and the same broadcast domain. 140 140
So what's the benefits of using an access point? 141 141
Well, it's going to allow you to connect your wired network 142 142
into the wireless domain and expand your access. 143 143
When you do this, 144 144
you can have one or multiple access points 145 145
that are connected to your domain. 146 146
For example, you can see that circular device here. 147 147
That's actually the access point I'm using in my building. 148 148
Because our building is a little bit larger 149 149
and we have concrete walls, 150 150
we have to have multiple access points working together, 151 151
so we don't have a drop in coverage 152 152
as we walk through the building. 153 153
We have three different floors of the building 154 154
and each one of those has an access point on it 155 155
that gives us full coverage throughout that building. 156 156
These access points all work together 157 157
and they hand off the client 158 158
from access point to access point, 159 159
as you walk around the building 160 160
or go up or down the stairs. 161 161
Now we're going to talk later 162 162
about how this actually works 163 163
and how these handoffs happen 164 164
from access point to access point in a separate video. 165 165
For the exam, I want you to remember 166 166
that Wireless Access Points extend your wired network 167 167
into the wireless spectrum. 168 168
So they're going to act like a hub 169 169
and a media converter, 170 170
converting those radio frequency waves 171 171
to ones and zeros, 172 172
that can be transmitted 173 173
over copper cabling of your wire network. 174 174
Next, we have what's referred to as a Wireless Router, 175 175
and this is a slightly different device. 176 176
Now what's the difference between a wireless router 177 177
and an access point? 178 178
Well a wireless router 179 179
is going to act as a gateway device. 180 180
And it's also going to act as a base station 181 181
for your wireless networks to communicate with. 182 182
This is the big difference here. 183 183
When you're using a wireless router, 184 184
instead of an access point, 185 185
you have this additional routing capability 186 186
inside the device. 187 187
Now, most people when they go to the store 188 188
to buy a wireless device, 189 189
they're going to get sold something marketed 190 190
as a wireless router. 191 191
This is really a combination of several devices, 192 192
all in one box. 193 193
For example, you can see here 194 194
that I have a Quantum Gateway Wireless Router from Verizon. 195 195
If you have a Verizon Fios connection in your house, 196 196
this is likely what you're using 197 197
to connect to the internet. 198 198
This one is a singular device 199 199
that has a wireless access point built into it. 200 200
And in addition to that, 201 201
there's a router built into it. 202 202
And in addition to that, 203 203
there's a four-port switch built into it, 204 204
and it also has a firewall built in, 205 205
and it has a fiber modem. 206 206
All of these different devices 207 207
have all been combined into the single small office, 208 208
home office user device 209 209
that is now sold as a wireless router 210 210
or a wireless gateway. 211 211
So on the exam, 212 212
remember a wireless access point is just that. 213 213
It's an access point 214 214
that's going to extend your physical network 215 215
into the wireless domain and it acts at layer one, 216 216
but a wireless router or wireless gateway 217 217
is going to be a combination device 218 218
that acts as a wireless access point and a router 219 219
within the same box.