Narrator: In this lecture I'd like 2 2
to talk about WiFi Bands. 3 3
The band of a network 4 4
defines what frequency it 5 5
can use to broadcast the signal. 6 6
This means it also defines 7 7
the frequency that the clients 8 8
or the computers need to be able 9 9
to support and use in order to 10 10
be able to connect this network. 11 11
The two main frequencies used in 12 12
WiFi networks are 2.4 and 5 gigzhertz. 13 13
Now previously, when we use airodump-ng 14 14
we were only sniffing on 15 15
the 2.4 gigahertz frequency. 16 16
You can see first of all 17 17
my wireless adapter is in 18 18
monitor mode mon0 in here. 19 19
So if I just do airodump-ng mon0 20 20
you'll see that I can get the 21 21
wireless networks around me. 22 22
But you might have noticed that 23 23
you won't actually see all the networks 24 24
around you when you run airodump-ng. 25 25
I'm gonna control-c this 26 26
and if I go here to 27 27
my normal host machine 28 28
and it actually has a 29 29
built in wireless adapter 30 30
so it's not as strong 31 31
as my alpha adapter. 32 32
But if I look for networks, 33 33
you'll see I actually have 34 34
much more networks in here. 35 35
And mainly I have networks and 36 36
in here and the name by 5G. 37 37
Now the network doesn't have 38 38
to necessarily end in 5G 39 39
but here in Ireland if 40 40
a network broadcasts over five gigahertz 41 41
the service provider adds 42 42
5G to the network name. 43 43
But we also have other networks 44 44
broadcasting over 5G 45 45
that don't end in 5G. 46 46
But basically the main point that 47 47
I want to talk about is I'm not able 48 48
to see all the networks around me 49 49
in here in airodump-ng. 50 50
And the reason for this is 51 51
because airodump-ng is only sniffing 52 52
on 2.0 gigahertz frequency. 53 53
So if you do this and you don't 54 54
see all the networks around you, 55 55
or if you're sniffing 56 56
on your own network, 57 57
but you don't see all the clients 58 58
in your network it's possible 59 59
that your routers is 60 60
broadcasting over two bands, 61 61
over 2.4 and five gigahertz. 62 62
And if you're not seeing 63 63
the router at all, 64 64
if you are not seeing the network 65 65
at all like what's happening 66 66
here for me, then the router 67 67
is probably just broadcasting 68 68
over five gigahertz. 69 69
Now this doesn't mean that 70 70
your wireless adapter is not good. 71 71
it just literally means that 72 72
this adapter is not able to 73 73
see five gigahertz frequency. 74 74
It's just outside of its limit, 75 75
outside of its reach. 76 76
The main problem with five gigahertz 77 77
is that, there are a lot 78 78
of wireless adapters that can 79 79
see it and can communicate with it. 80 80
But not many of them support 81 81
monitor mode and packet injection. 82 82
So you might see me and other people 83 83
recommending wireless adapters like 84 84
Alpha AWUS0360NHA 85 85
This is my most favorite wireless adapter. 86 86
I use it all the time, even now. 87 87
But the problem with that adapter is 88 88
it doesn't pick up five gigahertz frequency. 89 89
So it doesn't mean that that adapter is bad 90 90
it just means that it can't see 91 91
five gigahertz frequency. 92 92
Like I said, there aren't many 93 93
wireless adapters that support five gigahertz, 94 94
but I have an adapter here it's Alpha AWUS0360ACH 95 95
and this adapter supports both 96 96
2.4 gigahertz and five gigahertz frequencies. 97 97
It's not as good as the Alpha 98 98
but it does the job. 99 99
Now if you want more information about 100 100
wireless adapters check out 101 101
the link in the resources. 102 102
I'm not going to talk a lot about 103 103
what wireless adapters do. 104 104
But in this lecture I wanna show you 105 105
how to sniff and discover five gigahertz 106 106
frequency networks and then so that 107 107
you can use all the attacks that you've 108 108
learned in my other lecture and 109 109
in my previous videos with 110 110
five gigahertz networks. 111 111
So, the adapter that I'm using right now 112 112
supports five gigahertz but 113 113
as you can see, I still 114 114
can't pick up these networks. 115 115
That's because I need to specifically 116 116
tell airodump-ng that I want you 117 117
to listen on five gigahertz frequencies 118 118
and five gigahertz channels. 119 119
To do that, all we have to do is 120 120
just do airodump-ng like we always do 121 121
and then we are gonna use a new argument 122 122
that we haven't see before and 123 123
this argument is called band. 124 124
And we're gonna tell it that I want 125 125
you to sniff on band A 126 126
and that's the band that 127 127
supports five gigahertz frequency. 128 128
And then I'm just going to give it 129 129
the name of my wireless adapter 130 130
in monitor mode which is Mon0. 131 131
So the command is very simple. 132 132
It's very similar to what 133 133
we have used before. 134 134
And all we have to do 135 135
is just type in airodump-ng 136 136
followed by the band and 137 137
that band that we want to use is A 138 138
and we're following that with 139 139
our wireless interface. 140 140
So I'm gonna hit enter, 141 141
and as you can see as soon 142 142
as we hit this I'm actually just 143 143
gonna do control C now 'cause 144 144
you can see the results. 145 145
You can see that we got much more 146 146
networks right now and we have 147 147
the five gigahertz networks. 148 148
So we have this network and 149 149
this network that we 150 150
weren't able to see. 151 151
We have the JamesSmithWhiskey 152 152
newtwork as well. 153 153
And basically we're able to capture 154 154
all the networks that use the 155 155
five gigahertz frequency. 156 156
Now what you can also do, 157 157
let me clear the screen. 158 158
You can specify multiple bands 159 159
using the band argument. 160 160
So again, using the same command, 161 161
instead of just saying band A, 162 162
we can do band a-b-g 163 163
and what this will do is 164 164
it will tell airodump-ng to capture data 165 165
on both 2.4 and five gigahertz frequencies 166 166
at the same time. 167 167
So let me show you. 168 168
So as you can see right here 169 169
we're capturing some 2.4 gigahertz networks 170 170
and we're capturing five gigahertz networks 171 171
as well at the same time. 172 172
and we'll also be able to discover 173 173
clients connecting to both bands. 174 174
The only problem with using 175 175
airodump like this is first of all, 176 176
you need a powerful 177 177
wireless adapter to do this. 178 178
Also it will be slightly slower 179 179
than only sniffing on one band. 180 180
Because when you're sniffing on 181 181
two bands you have a lot of channels 182 182
that airodump-ng has to hop on 183 183
all of them and discover clients 184 184
and networks broadcasting on these channels. 185 185
So, if you want quicker results 186 186
then you're better off specifying the band A, 187 187
when you want to sniff on the 188 188
five gigahertz frequencies and just 189 189
not specify the band when sniffing on 2.4. 190 190
But, as you can see you can 191 191
just run the command like so, 192 192
with band a-b-g and this way you'll 193 193
be able to capture data sent over 194 194
2.4 and five gigahertz frequencies. 195 195
Also keep in mind, in order to sniff data 196 196
on five gigahertz frequency, like I said 197 197
your wireless adapter needs to 198 198
be able to support this band. 199 199
So simply adding the band argument 200 200
will not work unless your wireless adapter 201 201
can support and can sniff data on this band. 202 202
One more thing that I wanna note, 203 203
I've actually said this before. 204 204
If you run airodump-ng against a network 205 205
and you see some devices missing 206 206
then there is a high chance that these devices 207 207
are connected over five gigahertz. 208 208
So again, use the band A and then 209 209
you should be able to see these devices.