Module 11 wireless network security.
A couple of terms we're going to define here right off the bat.
We're not too terribly worried with full
definitions of everything on the slide, but an access point will be especially
interesting since we'll talk about that throughout the module.
An access point is used to connect
wireless devices to a wireless or wired network.
The BSSID is the MAC address of the access point that is set up a basic service set.
We'll talk about basic extended, independent service sets.
And then hotspots, great fun to be had with hotspots.
A place where a wireless network is available for public use.
Lots of fun to impersonate WiFi hotspots.
I can guarantee you, I can walk into any
public place with public WiFi, and within a matter of minutes, I can have somebody
connected to my phone thinking they're connected to the publicly available WiFi.
So you want to stay away from public WiFi
like the plague, it's nothing but risk and problems.
Always use your cell or connection or a VPN.
Some other wireless terminologies.
Association, the process of connecting a wireless device to an access point.
Now, we're going to talk about three
pieces of information that are useful that are provided with an association.
Number one is the SSID of the network if it's not being broadcast.
Number two is a PSK and a pre shared key handshake.
And number three are ARP requests for web
injection, which you would think after all these years, web being so darn insecure
that it's never used, but it still actually pops up all over the place.
So we'll talk a little bit about the weaknesses in web, WPA, PA2, etc.
And this association process can be forced through a deauthentication packet to a
connected client, forces them to reassociate.
You can pick up the SSID, the PSK, and Art request.
The service that identifier.
It's recommended that you don't broadcast your SSID.
It's a unique identifier of 32
alphanumeric characters given to a wireless, local area network.
That's your network name.
If you want to be found, you broadcast it so people can easily connect your network.
If you don't want to be found, you don't
broadcast it, but it shows up typically as a hidden network, which in my opinion,
makes it a little bit more suspicious than just broadcasting the SSID to begin with.
A best practice is to not broadcast the SSID if you don't want to be found.
The remaining terms on this slide,
orthogonal frequency division, multiplexing, or direct sequence spread,
or frequency hopping, these all deal with the subdivisions of the wireless channels
and the order in which they're accessed to transmit.
We're not going to really dig into that too much right now, but different
evolutions of 802.11 use different types of frequency division.
When you talk about compatibility between wireless devices, you want to be sure that
every device in the network supports the signal divisioning.
Of DM, DSSS, Bluetooth typically uses the frequency hopping spread spectrum.
Our wireless networks.
The advantage to a wireless network is no wires.
The disadvantage to a wireless network is
no wires, no physical constrainment of the signal, which there's a huge convenience
factor with not having to run network cables.
But also that brings in some serious
security concerns since you don't have to be connected to the physical medium to
interfere with or intercept of the user's traffic.
The advantages, of course, eliminates wiring.
I am of the opinion that you should always use hard wires if possible.
I just got done actually doing some rewiring of my house.
All the TVs, everything is set up for
Ethernet connections, but it's well worth it.
I've got a security piece of mind and I've
also got consistent bandwidth and no buffering.
When you can, it's always best to use
physical cabling, but that's not always completely convenient or practical.
Wifi defined uses radio waves or microwaves to
allow electronic devices to exchange data or connect to the Internet.
Bluetooth, most are familiar with the definition of Bluetooth, a fairly short
range wireless that allows you to transmit a data between cell phones, computers,
other network devices over short distances, typically up to about 30 feet.
We do have a couple of different flavors
of Bluetooth, but Bluetooth is quite often used in personal area networks, which are
networks in close proximity to your person.
Rfid is a short range wireless as well.
A lot of times this is used for tracking
objects, using tracking tags and other applications.
Then YMAX is a long distance wireless networking high speed Internet, belongs to
the I E 802.16 family of wireless networking standards.
In some more rural areas, your high speed access may actually be provided by some a
wireless, depending on how close you are to the repeaters in the towers,
performance is up and down, again, depending on distance.
Wireless standards.
In the 802.11 standard, 802 in general
defines layer two types of technologies and communications.
The 802.11, 802.2 standard, 802.2 is logical link control, 802.3, 5, 11, 15,
16, etc, are all different MAC sublayer technologies or protocols.
In 802.11, we have a few different evolutions of wireless.
We started off with A, B, G, there's N, A, C, A, D, and a few others.
They vary by the frequency that they use, by the bandwidth and the data stream rates
in megabits per second that they perform at, by their modulation, and by the range.
Now, you're going to want to be familiar with more basic flavors of wireless.
B, G, N, A, C, A, D.
We're this is all potentially fair game
for the exam, but those are some of the most common standards.
All right, wireless network topologies.
A couple of different infrastructure models.
An ad hoc standalone network architecture
is referred to as an independent basic service set.
It is a standalone hub, multiple clients, single access point.
Infrast network topology, centrally
coordinated architecture basic service set is devices connected through an AP.
The AP connects to the internet via a
modem or there's an uplink somewhere installed in large organizations.
This is then linked to the outside world.
Typically, we think of basic service sets or extended service sets which are
multiple APIs servicing the same wireless land.
Classifications of wireless networks.
A wireless network can be an extension to
a wired network, which is quite often the case.
By connecting to the wireless network, you
have the ability to attack wired clients as well or communicate with them.
Attack malicious, communicate non malicious.
Multiple access points.
This is referred to as an extended service set.
Multiple APIs, service in the same wireless land.
Land to land wireless network, you've got
a bridge between two wired lands or subnets.
Then 4G hotspots, like I said, you're
going to have lots of fun with your wireless hotspot.
You can really call your network anything you like.
I'll tell you a quick story about that when the appropriate slide turns.
Got a few more like that as well.
My classification of wireless networks.
Wireless networks based on geographic area coverage.
You have the wireless WAN, which is
typically a single room to an entire campus.
You have the wireless WAN, which covers a
larger area, region, nation, or even the entire globe.
You have a WPAN, which is Interconnects devices positioned around an individual.
Personality network, typically like Bluetooth, things like that.
Then wireless MAN, broadband area networks
using an exterior antenna, good alternative for a fixed line network.
Again, some municipalities have free
wireless, high speed connectivity or broadband available.
Used to have it actually in Saint Louis
Park where I lived in Minnesota at one point.
It was okay.
They had varying reports back on throughputs and reliability.
The components of a wireless network.
The access point, we've already defined, the wireless NIC.
At the very least, you need NICs, you need AAPs.
However, you can also have NIC to NIC transmission.
We'll call those an ad hoc connection.
The wireless modem transmits network signals to other units without requiring
physical cabling, and then the wireless bridge.
Again, this is an up link, and the bridge is the link between two wired networks.
Little bit of redundancy here.
The wireless repeater, the re transmits the existing signal captured from a
wireless router that's meant for increasing transmission distance.
Wireless router performs the functions of
a router as well as AP, provides Internet access to various devices.
That whole modem functionality, routed functionality, one of the same.
They're still providing an uplink to the
internet through some routed gateway type of connection.
Wireless gateways, route data packets, functions as wireless AP, internet
connection can be shared between multiple stations.
Then the USB adapters are just wireless
adapters you plug into a USB port, really convenient.
All right, antennas.
You can have all sorts of fun with your wireless equipment.
I got really into this initially with my
YAGI antennas and my parabolic grids and my Radio Shack antenna rotator I had up in
the attic that I could rotate from a cool little compass looking dial on my desk.
Had a lot of fun with that.
But antennas can focus their transmission
energy in a single direction or in all directions uniformly.
An omnidirectional provides a 360 degree horizontal radiation pattern.
That's your typical rubber ducky antenna.
Directionals are used to transmit in one direction.
You've got YAGI antennas, which are a great example of directionals.
That is the Cantana specification or format.
You may build the Pringles can, build one yourself.
You have an antenna with a bunch of vertical stanchions on it, put in some a
weatherproofing cylinder and you can aim it.
The parabolic grid looks like direct PC satellite dishes.
Not the most stealthy antenna.
Yags are a small form factor.
They can be concealed, be a little bit more covert.
Parabolics are big giant dish looking things.
They look conspicuous.
A dipole antenna, by the way, directional, and then reflect your antennas,
concentrating electromagnetic energy ready to receive at a focal point.
We got directionals, we got omnidirectionals.
We got YAGs, we got parabolic.