Hello everyone and welcome to our second to last lesson, we can see the light at the end
of the tunnel, we're almost done here, of our Encore Wireless course.
We're going to be talking about the features that you might see on the exam.
These are the things you configure at the AP level or at the wireless LAN controller
level that help control traffic, that give you a little bit of the features that would
help shape your traffic and make things better in your environment, the special things you're
looking to do.
I'm going to take myself off the screen so you can see everything here.
Aggressive load balancing.
Now, aggressive load balancing sounds like, this is what it sounds like and it's not.
It sounds like it would take clients from an AP, let's, looks like I did it yet again
with the controller, hang on, hang on here.
So it looks like what would happen is you take an AP and you've got these clients who
are connected to the AP.
Aggressive load balancing sounds like you would take these clients and, oh, there's
too many on this AP right now, I'm going to shift them over immediately.
That's what aggressive load balancing sounds like.
And that is not what it is.
Some people read that for the feature and they assume that's what it is.
It is not.
Aggressive load balancing can move across access points and even wireless LAN controllers
in the association phase of a laptop or whatever you are using to connect to your phone or
whatever.
So during that association phase, when you're working with that AP, the AP can send out
a notice that says, hey, I'm too busy, and this is called a code 17.
I'm too busy.
I want you to find another AP.
Now another thing that's important to know is this is OS dependent.
Some OSs can say, nah, I'm good.
I'm still going to connect to you.
A lot of people don't understand that the OS in the equation of connecting to your wireless
network has a lot of control over what happens.
The operating system will actually decide if a signal strength is too low or high.
If you're in the middle between two cells, let's say I'm in the middle of this cell and
this cell, and there's an overlap, like I have another user who's here, right?
Your OS is actually the one that decides am I going to join here or I'm going to join
here.
And sometimes they can even override if the AP sends, say the AP sends that code 17.
I'm too busy.
Connect to somebody else.
The OS can go, no, I would like to associate with you.
So it's very interesting.
You can enable or disable load balancing on that wireless LAN level.
And this is very important for voice.
You really want to make sure you know what's going on in voice.
I actually don't recommend using wireless for voice clients.
But if this is something you're doing, you're using the latest and greatest technologies,
it's not as bad as it once was.
But it's something I still don't recommend.
There's jitter.
There's other things that come into play that wireless is just not as good at.
Here's something I want you to note.
I'm not going to read this to you.
You're not children.
I want you to note and read this information right here.
This is important.
What this is about is voice clients, right?
When voice clients do not authenticate more than 300 milliseconds, that's a problem.
So you're going to have to do your own configuration.
You're going to have to go in and change the CCKM and make sure that there's a pageant
router between the AP and wireless LAN controller.
So if I have an AP and I've got a router and then the wireless LAN controller, I want
to make sure that's there and want to make sure that there's a configuration delay of
600 milliseconds, that's 300 milliseconds up and 300 milliseconds down.
Take a second, read that, understand that.
And that's just to avoid that authentication problem.
If it doesn't authenticate, it's going to fail.
So voice clients really need this additional setup.
This is just yet another reason why I don't recommend wireless for voice clients.
You have a better option in most cases.
Let me show you why.
Remember when I underline something, you need to know it.
So read through that one more time, pause the video, read through it one more time,
understand why.
We've got too much delay between the wireless infrastructure and the wireless LAN controller.
You want to build in a little bit of leeway there by adding in that configuration with
the CCKF.
Hey, I said it.
I said it right too, wow.
Let's talk a little bit about the next feature on our list, which is peer-to-peer blocking.
Now peer-to-peer blocking allows us to control how the traffic is directed in our environment.
If I have an AP here and an AP here, I don't know why my APs look like robot martians,
but they always do.
So we have an AP there, AP there, and I have a client here, and I have a client here.
I always do laptops.
That's what those are, by the way.
They're very poorly drawn laptops.
Laptop there, and I have a laptop here.
I don't want anybody to be able to talk to each other on my wireless network.
Let's say it's a guest VLAN or a guest wireless LAN.
That makes sense.
I don't want peer-to-peer communication.
So I could shut this off.
This is bridged locally and dropped by the controller and forwarded upstream to the VLAN,
so it's going to be forwarded up so that there's no peer-to-peer.
This is applied directly to our wireless LANs.
This is a setting there, and this does not apply to that multicast traffic.
Multicast traffic is still going to go out.
This is locally and centrally switched wireless LANs.
Disabled is the default value.
That means we bridge locally within the controller.
This is the part I'd like you to remember here.
This is the important part.
Drop means the controller, the wireless LAN controller, is going to discard that peer-to-peer
traffic and forward upstream.
Packets are forwarded to the VLAN and upstream devices, and then they may come back down.
So those are the different configurations you have.
This is a very important one at the bottom.
For FlexConnect local switching, select drop from the P2P blocking drop-down list, and
then select FlexConnect local switching checkbox.
This is the configuration you have to use if you have FlexConnect local switching enabled
and you want peer-to-peer blocking.
So make sure this is the setting you understand, okay?
Peer-to-peer blocking has its use cases.
Like I said, I guess wireless LANs, more secure wireless LANs, or maybe you just want to keep
people from doing certain things, sharing different things over the wireless network.
Maybe file sharing is not something you want to do.
Printers are kind of cool for this.
You don't want peer-to-peer sharing on printers a lot of the time.
So this is the kind of thing I would do there.
All right, next feature, dynamic channel assignment.
Now this is good and bad, and we'll dive into it.
Now this is part of Cisco's radio resource management.
So when we're talking about dynamic channels, we're really talking about frequencies, right?
We talked about frequencies very early on, and we talked about the different channels,
if you remember that.
Every frequency has a number of channels.
I might have one, six, eleven, three channels.
Maybe I'm using the 2.4 gigahertz range.
Maybe I'm using the 5 gigahertz range, and I have much more channels.
But this dynamic channel assignment means that we're going to change those channels
based on a cost metric.
We're going to evaluate how our channels are performing.
And this is evaluated based on AP load, interference, adjacent channel interference, and non-Wi-Fi
sourced interference.
This is an important one, non-Wi-Fi.
What is non-Wi-Fi sourced interference?
Well, did you know that a microwave can put out frequencies that can mess with your wireless?
That is non-Wi-Fi sourced interference.
We have too much energy in the air that's just messing with our frequencies.
So this is all taken into account and given a cost metric that the dynamic channel assignment
then evaluates.
This is configured under A, N, A, C, B, G, and these are the ones that are supported.
We can set this to run automatically.
So that's cool, right?
So I'm automatically going to check every 10 minutes.
That's the default, every 10 minutes.
And there's an anchor point, which is the time of day that the algorithm will start,
and then it's 10 minutes from there.
So if I set it up to start at 11 p.m., 11.10 p.m. it's going to run, 11.20 p.m. it's going
to run, and so on.
And it's going to go through this cost metric, and it's going to evaluate the channel I'm
on.
If that channel's being interfered with, or there's another Wi-Fi channel very close,
somebody's using an off channel, somebody's using five, and I'm using six, oh my goodness,
that's going to be a problem because there's lots of overlap there, right?
What's going to happen is we're going to change channels, and that's great, except for one
thing.
During a channel change, you are going to be disconnected briefly.
So if you have a client who's constantly disconnecting every 10 minutes, this is something I would
look at.
I would look at the dynamic channel assignment and see just how bad this cost metric is.
How bad is the interference?
And if it is worth switching channels every 10 minutes.
You guys might see this, somewhere you might see this is at the airport, or a Doppler radar.
We kind of talked about that.
They have some interference there at the five gigahertz range, and if you have dynamic channel
assignment, when they turn on that radar, if you're near a news station, you're going
to see this, and then you're going to see your channel start changing at 10 minutes,
at 10 minute intervals.
And it might even change multiple times as they have the radar enabled.
Freeze does not run the DSA algorithm unless triggered.
So you would have to, that's a more manual process.
You're going to have to say, hey, I want you to evaluate this, and off disables it altogether.
So this is still running, by the way.
This is still running, but not every 10 minutes.
You're kind of in a pause state until you turn it back on.
So kind of a cool feature, but can be a problem, right?
It can be more trouble than it's worth.
If you're constantly switching every 10 minutes, because when you switch a channel, everybody
drops because the frequency's changed.
Everybody's got to move to the new frequency.
Think of it this way.
If I was using a two-way radio, and I was changing the channel on the two-way radio,
I have to tell you, hey, we're moving to channel seven.
You would respond, understood, moving to channel seven, over, move to channel seven.
So during that movement period, we are down, and that's exactly, well, not exactly.
That's kind of the situation we run into.
All right.
Another thing we need to cover for our Encore exam is manually adding a wireless SSD to
a client.
Now, some of you just kind of tilted your head, manually adding.
I just click on the button, and I see that my SSID is there, and I click on that.
Well, some of those people out there like to hide their SSID through a, it's kind of
a security setting.
Now, I have problems with this.
It's kind of a security setting.
It's not really a security setting in my book.
I am a, I love security.
I do a lot of security stuff.
Security through obscurity is not necessarily a good practice.
Security through obscurity is a slowdown tactic for security.
You know, in security, you have, I'm not going to dive too deep into this, but this is not
to be considered a security setting in my book.
Some people disagree with me, and I understand their rationale.
Security through obscurity, or trying to make it harder to find something, is not true security
in the sense that if I have the right tools, this is, you're done immediately, and you
can say that for a lot of security vulnerabilities, for sure, but I don't like this type of security
feature, right?
But I digress.
Lots of people hide their SSID.
It's not a bad idea.
I don't have anything against those.
Just don't call it security in my book.
SSIDs, hiding an SSID means I'm not going to broadcast it out to the world.
Nothing's changed, but I don't have that beacon that says, my network's right here.
My wireless LAN network's right here.
This SSID is being broadcast from this AP.
So in order to configure your clients to use that AP, you have to manually add the
wireless SSID, and you do that in Windows Client by manually adding it.
In Windows 11, you go to Network Wi-Fi, it's right here, Manage Known Networks, and then
right here, you have to click Add a New Network.
The Add a New Network comes up with this window in which you have to put in the network
name.
So you have to remember the network name and put it in.
Security type will be filled out there.
Connect automatically.
You would want to click that if it's an environment you visit often.
If you're on a business trip or something, do not connect even if the network is not
broadcasting.
This has to be checked, okay?
So that's how you do that.
Again, I don't consider this a security setting, but I know lots of security experts who would
both agree and disagree with me there.
I'm just not a fan of security through obscurity.
And that wraps up our different features you might see on the Encore exam.
We have one more lesson after this.
It's about web authentication and basically setting up your guest premises and using that
browser as kind of your portal into the wireless network.
But that's it for this lesson.
I'll see you in the next one.