Narrator: In this lecture I'd like
to talk about WiFi Bands.
The band of a network
defines what frequency it
can use to broadcast the signal.
This means it also defines
the frequency that the clients
or the computers need to be able
to support and use in order to
be able to connect this network.
The two main frequencies used in
WiFi networks are 2.4 and 5 gigzhertz.
Now previously, when we use airodump-ng
we were only sniffing on
the 2.4 gigahertz frequency.
You can see first of all
my wireless adapter is in
monitor mode mon0 in here.
So if I just do airodump-ng mon0
you'll see that I can get the
wireless networks around me.
But you might have noticed that
you won't actually see all the networks
around you when you run airodump-ng.
I'm gonna control-c this
and if I go here to
my normal host machine
and it actually has a
built in wireless adapter
so it's not as strong
as my alpha adapter.
But if I look for networks,
you'll see I actually have
much more networks in here.
And mainly I have networks and
in here and the name by 5G.
Now the network doesn't have
to necessarily end in 5G
but here in Ireland if
a network broadcasts over five gigahertz
the service provider adds
5G to the network name.
But we also have other networks
broadcasting over 5G
that don't end in 5G.
But basically the main point that
I want to talk about is I'm not able
to see all the networks around me
in here in airodump-ng.
And the reason for this is
because airodump-ng is only sniffing
on 2.0 gigahertz frequency.
So if you do this and you don't
see all the networks around you,
or if you're sniffing
on your own network,
but you don't see all the clients
in your network it's possible
that your routers is
broadcasting over two bands,
over 2.4 and five gigahertz.
And if you're not seeing
the router at all,
if you are not seeing the network
at all like what's happening
here for me, then the router
is probably just broadcasting
over five gigahertz.
Now this doesn't mean that
your wireless adapter is not good.
it just literally means that
this adapter is not able to
see five gigahertz frequency.
It's just outside of its limit,
outside of its reach.
The main problem with five gigahertz
is that, there are a lot
of wireless adapters that can
see it and can communicate with it.
But not many of them support
monitor mode and packet injection.
So you might see me and other people
recommending wireless adapters like
Alpha AWUS0360NHA
This is my most favorite wireless adapter.
I use it all the time, even now.
But the problem with that adapter is
it doesn't pick up five gigahertz frequency.
So it doesn't mean that that adapter is bad
it just means that it can't see
five gigahertz frequency.
Like I said, there aren't many
wireless adapters that support five gigahertz,
but I have an adapter here it's Alpha AWUS0360ACH
and this adapter supports both
2.4 gigahertz and five gigahertz frequencies.
It's not as good as the Alpha
but it does the job.
Now if you want more information about
wireless adapters check out
the link in the resources.
I'm not going to talk a lot about
what wireless adapters do.
But in this lecture I wanna show you
how to sniff and discover five gigahertz
frequency networks and then so that
you can use all the attacks that you've
learned in my other lecture and
in my previous videos with
five gigahertz networks.
So, the adapter that I'm using right now
supports five gigahertz but
as you can see, I still
can't pick up these networks.
That's because I need to specifically
tell airodump-ng that I want you
to listen on five gigahertz frequencies
and five gigahertz channels.
To do that, all we have to do is
just do airodump-ng like we always do
and then we are gonna use a new argument
that we haven't see before and
this argument is called band.
And we're gonna tell it that I want
you to sniff on band A
and that's the band that
supports five gigahertz frequency.
And then I'm just going to give it
the name of my wireless adapter
in monitor mode which is Mon0.
So the command is very simple.
It's very similar to what
we have used before.
And all we have to do
is just type in airodump-ng
followed by the band and
that band that we want to use is A
and we're following that with
our wireless interface.
So I'm gonna hit enter,
and as you can see as soon
as we hit this I'm actually just
gonna do control C now 'cause
you can see the results.
You can see that we got much more
networks right now and we have
the five gigahertz networks.
So we have this network and
this network that we
weren't able to see.
We have the JamesSmithWhiskey
newtwork as well.
And basically we're able to capture
all the networks that use the
five gigahertz frequency.
Now what you can also do,
let me clear the screen.
You can specify multiple bands
using the band argument.
So again, using the same command,
instead of just saying band A,
we can do band a-b-g
and what this will do is
it will tell airodump-ng to capture data
on both 2.4 and five gigahertz frequencies
at the same time.
So let me show you.
So as you can see right here
we're capturing some 2.4 gigahertz networks
and we're capturing five gigahertz networks
as well at the same time.
and we'll also be able to discover
clients connecting to both bands.
The only problem with using
airodump like this is first of all,
you need a powerful
wireless adapter to do this.
Also it will be slightly slower
than only sniffing on one band.
Because when you're sniffing on
two bands you have a lot of channels
that airodump-ng has to hop on
all of them and discover clients
and networks broadcasting on these channels.
So, if you want quicker results
then you're better off specifying the band A,
when you want to sniff on the
five gigahertz frequencies and just
not specify the band when sniffing on 2.4.
But, as you can see you can
just run the command like so,
with band a-b-g and this way you'll
be able to capture data sent over
2.4 and five gigahertz frequencies.
Also keep in mind, in order to sniff data
on five gigahertz frequency, like I said
your wireless adapter needs to
be able to support this band.
So simply adding the band argument
will not work unless your wireless adapter
can support and can sniff data on this band.
One more thing that I wanna note,
I've actually said this before.
If you run airodump-ng against a network
and you see some devices missing
then there is a high chance that these devices
are connected over five gigahertz.
So again, use the band A and then
you should be able to see these devices.