- Back in 1997, someone had this awesome idea
to take wired ethernet and make it wireless.
And the term wireless local area network was born or WLAN.
It's an IEEE standard 802.11.
And in 1999, 802.11b is what became popularized
because prices were coming down
and you could buy a PCMCIA card
and join Wi-Fi networks.
And it was pretty neat
'cause you didn't need to have this
wired ethernet cable coming into your computer.
It was a little bit slower,
but it was quite a bit more convenient.
Common deployment methodologies or thoughts here.
So small office, home office,
coffee shop, et cetera,
you have a wireless LAN router,
client connects to that wireless LAN.
It's wireless from client to the router,
which is then wired up towards the internet.
Over in the enterprise side of things,
it's pretty common to see
a wireless access point that is bridging
layer two into a switched environment
and then routed out to the internet.
The key point here, though,
it is still IP, it's still ethernet networking.
What's the difference
between attacking a wired ethernet network
and a wireless ethernet network?
It's simply that connection medium.
It's still IP.
We still have MAC addresses.
Layer two is still the same.
It's the physical connectivity that changes.
IEEE standards have grown and evolved over time.
Started at 802.11b back in 1999,
went up to 802.11a, g, n, ac,
and now latest 802.11ax,
which gives us very fast wireless connectivity
with a range of frequencies.
So we are still sitting in ISM bands here,
2.4 gig and 5.8 gig in order to comply
with licensing worldwide
or rather frequency allocations worldwide.
Wireless LAN SSIDs.
So the name of a wireless LAN will be an SSID.
SSID stands for service set identifier,
and it distinguishes wireless LANs in the same airspace.
There is nothing stopping me
from having 10 wireless LANs
surrounding me right now.
And they could all have different names
and I could pick the one I want to connect to.
So we have overlapping airspace, right?
So whatever channel this router chooses to use
could overlap with the channel on this one.
So it's a contested medium,
the air that is.
SSID are 32 bites and often human readable,
though they don't have to be.
However, if you're gonna type in that SSID,
it's probably gotta be ASCII.
A BSSID distinguishes access points
on these same wireless LAN.
The distinguishing point here
is the MAC address of the access point itself.
So I have an example of that here.
We have the same wireless land SSID
with two separate access points.
They would have different BSSIDs.
That BSSID would be the MAC address,
but using the same wireless LAN name.
Infrastructure mode versus ad hoc mode.
In infrastructure mode,
you're going to connect to an access point,
which is part of the infrastructure.
And it's going to give you layer two,
layer three, layer seven connectivity.
Ad hoc mode will also give you layer two
through seven connectivity.
However, you are connecting point-to-point.
With access point to client,
you have what is an access point
and then the client connecting to it.
In ad hoc mode, there is no access point.
It's two devices talking directly to each other.
Security algorithms.
If this was all unencrypted,
open networks, no authentication,
there would be so much hacking going on.
(laughs)
'Cause the wireless networking
is so prevalent these days,
anywhere you go, you open your laptop
and you see 20 to 30 wireless networks
that you can connect to.
The majority of them
are gonna have some form of security employed.
It started with WEP, which was particularly insecure.
We're gonna talk about WEP,
and WPA, WPA2, and 3 in a coming lesson.
As we move down the list here,
we become more and more secure.