- [Instructor] We've discussed access point modes
in a previous video when discussing
wireless deployment models.
And here, we want to take another look at this concept.
When wireless networks were first developed,
all access points operated in Autonomous Mode.
Autonomous Mode means that each access point works
as a standalone device with no knowledge
of other access points that may be in the network.
We refer to these as a controller-less mode
of deployment, because there's no need
for a centralized controller to control
or to configure an autonomous access point.
These are very common still, especially
in small office and home office environments.
In fact, it's very likely that you have
an autonomous access point in your own residence
because they're cheap and they're easy to deploy,
especially if you don't need really broad coverage.
You may even run across older enterprise deployments
that still use several autonomous access points.
I worked with a client several years ago to upgrade
their wireless system from this exact configuration.
They had about six autonomous access points
throughout their office, all using the same SSID,
but each access point required individual configuration
and management if any changes were needed.
So for example, if you needed to change the wifi password,
this would need to be configured
on each individual access point,
which is obviously not ideal
from an administrative standpoint.
The general rule of thumb is that once you need
more than four access points, it's a good time
to consider taking a look at lightweight access points
from a cost perspective, and that's typically around
what we consider to be the breakeven point
between autonomous and lightweight deployments.
In order to manage an autonomous access point,
each device is configured with a management IP address.
From any device that is connected to the SSID provided
by the access point, you can launch
a browser and navigate to the management IP address.
There, you'd be able to log in and gain access
to the management and configuration menus.
Much more commonly seen in large enterprise environments
are access points running in Lightweight Mode.
Lightweight access points are just what they sound like.
They are simply lightweight hardware
that propagate an SSID throughout an area,
of which are under control
from a centralized wireless LAN controller.
Many Cisco solutions today
are software-based LAN controller services,
but there are certainly hardware based solutions
still out there as well.
The big advantage, obviously, is that you don't have
to make configuration changes
at each individual access points.
Rather, you can manage those
at a centralized controller instead.
These changes made on the controller
are propagated out to the lightweight access points,
so management is much, much easier with this model,
which is why this is a preferred method
for large enterprise environments.
As an example of how a lightweight
topology would fit together,
we can see here one of our network switches,
which connects back to our main network infrastructure,
and from there, we have
a centralized wireless LAN controller
connecting to our switch.
This bridges out our main network
with the lightweight access points.
These lightweight access points typically don't even require
the need for a nearby electrical wall socket,
since they can run POE, power-over-ethernet.
POE is a technology that allows the network cables
to carry both data and power.
So this makes the deployment that much easier to install.
Another thing to make mention of is the protocol used
between the wireless LAN controller
and the lightweight access points,
which is the Control and Provisioning
of Wireless Access Points Protocol, or CAPWAP, for short.
This is based on the older LWAPP protocol,
the Lightweight Access Point Protocol.
When a lightweight access point
is registered with the wireless LAN controller,
a CAPWAP tunnel is formed between the devices.
This allows for an encrypted exchange
of control and configuration-based messages between
the lightweight access points
and the wireless LAN controller.
On many newer controllers, which are more robust
and have much more hardware resources available,
the user traffic is also encrypted
as it passes between these devices.
This is becoming more commonplace.
So unless you have an older setup,
both the client and the management traffic
are likely to be protected by encryption.
It's also important that you know
the different modes that lightweight access points
are capable of running.
From a Cisco wireless LAN controller,
you can configure the lightweight APs
in several so-called special purpose modes.
So let's define each of those.
The first one is Local Mode.
This is the default mode for the access point,
and it performs all of the normal operations
that you'd expect, so it would provide
an SSID and wireless coverage.
If the access point is not actively in use transmitting,
then it will perform background operations.
Things such as measuring signal interference nearby,
and checking for rogue devices on the network.
Next, we have Monitor Mode.
In this mode, the lightweight access point
would only perform those duties mentioned
as background operations in Local Mode.
This access point would not transmit any data at all,
but it would only be used for things
like checking IDS events, rogue access point detection,
and location-based services, among many other things.
Then there's FlexConnect Mode.
This was covered in a previous video as well,
and this mode allows for the management
of lightweight access points at a remote office
from a central controller at a main office.
This management all happens over a WAN connection,
and it's all encrypted.
There's Sniffer Mode, which is essentially
a packet capture mode.
An AP would be dedicated to receiving wireless traffic
and routing the data that's received
to a traffic analyzer, something such as Wireshark
that you may be familiar with.
There's also Rogue Detector Mode.
This mode would be where an AP is solely dedicated
to discovering rogue devices.
This is done by checking MAC addresses of clients
against a list of known addresses
in order to present MAC spoofing.
And then there's Bridge Mode,
which can bridge together two locations.
Multiple access points in Bridge Mode
can be used to create a mesh network
as a point to point or point to multi-point bridge.
We can also combine Bridging and FlexConnect Modes
to offer a mesh network that is able
to be controlled centrally from a main office
over to a remote office location.
This mode is called Flex+Bridge Mode.
And the last one to mention is SE-Connect Mode.
Here, the access point would solely operate
as a spectrum analyzer to gather information
about all of the available wireless channels.
Just as with Sniffer Mode, this information
would be forwarded to some sort of analyzer tool.
In this case, it would be a tool specialized
for wireless spectrum data analysis.
The Cisco tool for this is called Cisco Spectrum Expert,
which is where the SE in SE-Connect comes from.
That stands for Spectrum Expert in this mode.
So that's a look at the two common modes
for access points, which are lightweight
and autonomous operating modes, and an overview
of the sub-modes available for configuration
when we're using lightweight Cisco access points.