All language subtitles for Free-CCNA-WAN-Architectures-Day-53-CCNA-200-301-Complete-Course_en

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In this video we’ll look at WAN architectures.

Specifically, we’ll be covering topic 1.2.d,\n

Both of these exam topics use the term ‘describe’,\n

You just need a basic understanding of some\n

Note that we’ll be looking at WANs from\n

the customer of a service provider, not from\n

To learn more about the service provider perspective,\n

Here’s what we’ll cover in this video.

First I’ll give an introduction to WANs\n

Then I’ll introduce one type of connection\n

Then another WAN technology known as MPLS,\n

us with a kind of VPN, virtual private network.

Then I’ll introduce some options for internet\n

VPNs, which allow us to create virtual private\n

So, we’ll cover a lot of topics, but we\n

To cover just the topic of MPLS in depth,\n

least as long as this entire CCNA course.

For the CCNA exam, all that’s expected is\n

technologies and their purpose.

As always, make sure to watch until the end\n

from Boson Software’s ExSim for CCNA, the\n

Okay let me introduce the concept of WANs\nfirst.

As you know already, WAN stands for Wide Area\n

A WAN is a network that extends over a large\ngeographic area.

For example, between cities, between countries,\netc.

So, WANs are used to connect geographically\nseparate LANs.

For example, if a company has an office in\n

in London, each of those offices is a LAN,\n

them form a WAN, Wide Area Network.

Although the Internet itself can be considered\n

to an enterprise’s private connections that\n

So, as I said the Internet can be considered\n

Although there is another kind of technology\n

Over public and shared connections like the\n

can be used to create private connections.

I’ll show you a few kinds of VPNs in this\nvideo.

Note that there have been many different WAN\n

Depending on the location, some will be available\n

I won’t cover every possible WAN technology\nin this video.

Also, technologies which are considered legacy\n

Legacy basically means old and no longer used\nor rarely used.

This enterprise has a central data center\nand some offices.

For the purpose of this video we’re not\n

of the devices in each LAN, but each of these,\n

Each office is connected to the data center\n

physical connection between two sites.

This is not a shared connection, it’s not\n

connection that the company uses to connect\nits sites together.

By the way, do you know a word for this kind\n

In the last video I introduced the term star\n

a more common term is hub and spoke.

The central site, the data center, is called\n

One major advantage of a hub-and-spoke topology,\n

it’s easier to centrally control what traffic\n

All traffic between offices can be sent to\n

and it can control which traffic is allowed\nand which isn’t.

So, remember that term, hub and spoke topology.

Now, I have to say that this diagram is actually\n

This is a better representation of what’s\nactually going on.

Rather than a single physical cable directly\n

a service provider, which connects the sites\ntogether.

I will introduce leased lines soon, but these\n

I briefly introduced serial connections in\n

2 encapsulations like HDLC and PPP, not Ethernet.

However these days WAN connections via Ethernet\n

Optical fiber connections allow much longer\n

cables, so these days WANs using Ethernet\n

Note that the CCNA focuses on the WAN connection\n

So we won’t spend much time talking about\n

provider network, the gray box in this slide\n

If you want to learn more about that, consider\n

Now, the Internet can also be used for an\n

However, the Internet itself is not a private\nnetwork.

It’s a shared, public network, so sending\n

In this case, note that each site has a physical\n

However, to send traffic between sites the\n

We’ll cover these in greater detail soon,\n

so that the contents can only be read by the\n

Then, the encrypted packet is encapsulated\n

This means that the original packet will remain\n

Okay, so that was a quick introduction to\na few WAN options.

Now let’s take a slightly deeper look at\n

A leased line is a dedicated physical link,\n

As I mentioned before, they use serial connections\n

So, these aren’t Ethernet links.

The layer 2 encapsulation is not Ethernet,\n

There are various standards that provide different\n

This chart from Wikipedia shows some of the\nstandards.

Now, there are a lot here and I don’t think\n

Of course, if you want you can make flashcards\n

and their speeds, but I think that will be\n

In North America the standard names begin\n

I will include flashcards for these three\n

one except a few people at Cisco know exactly\n

to you if you want to memorize more or not.

In Europe, as well as other regions, the standards\n

Again, I will include flashcards for these\nthree standards.

Now, as I mentioned before Ethernet WAN technologies\n

It’s because leased lines tend to have a\n

meaning it takes a longer time to actually\n

speeds than Ethernet connections provide.

Okay let’s move on to another WAN option,\nMPLS.

MPLS stands for Multi Protocol Label Switching.

Similar to the Internet, service providers’\n

many customer enterprises connect to and share\n

However, the label switching in the name of\n

to be created over the MPLS infrastructure\n

These labels are used to separate the traffic\n

the shared infrastructure, and make sure it\n

There are a few basic terms you should know\nfor MPLS.

CE router means Customer Edge router.

This is the customer’s router that is connected\n

Finally there are P routers, these are the\n

edge of the network and don’t connect to\ncustomer routers.

This diagram should make it easier to understand.

Notice the CE routers are at the edge of the\n

PE routers, the provider edge routers.

Within the provider network there are also\n

infrastructure of the service provider’s\n

When the PE routers receive frames from the\n

This label is actually placed in between the\n

header, so sometimes MPLS is called a Layer\n2.5 protocol.

These labels are then used to make forwarding\n

In regular IP routing the router checks the\n

table to decide where to forward the packet.

MPLS routers use the MPLS label to decide\n

Now, the CE routers do not use MPLS, it is\n

The CE routers do not have to run MPLS or\n

Now, there are a few different kinds of VPNs\n

When using a Layer 3 MPLS VPN, the CE and\n

Now, it doesn’t have to be OSPF, it could\n

Or the customer could just write static routes,\n

But let’s assume a routing protocol is being\nused.

For example, in the diagram below office A’s\n

CE will peer with the other PE, like this.

Then, office A’s CE will learn about office\n

B’s CE will learn about office A’s routes,\ntoo.

So, this is a Layer 3 MPLS VPN.

The CE routers either form dynamic routing\n

they use the PE routers as the next hop of\ntheir static routes.

A Layer 2 MPLS VPN can also be used, in which\n

So, the entire service provider network is\n

Although the CE routers will physically connect\n

CE routers are directly connected.

Their WAN interfaces will be in the same subnet.

If a routing protocol is used, the two CE\n

In this case, the service provider network\n

it’s doing so in a way that it’s like\n

a big switch connecting the two CE routers\ntogether like this.

The CE routers are physically connected to\n

is operating like a big switch connecting\n

Now, MPLS is a technology that runs in the\n

technologies, many different kinds of connections,\n

provider’s MPLS network for WAN service.

In this case office A and office B are connecting\n

Perhaps office C is connecting to the service\n

Office D might be connecting via CATV, a cable\n

And office E might use a serial connection,\n

So, these sites are connecting to the service\n

and they will all be able to communicate with\n

For the CCNA exam, you should know that MPLS\n

You should know the terms CE router, PE router,\nand P router.

You should know that Layer 3 MPLS VPNs have\n

using a routing protocol such as OSPF, whereas\n

are all directly connected to each other.

The service provider routers are totally transparent,\n

As I mentioned at the beginning of this video,\n

a huge course to cover in depth, but let’s\n

Before focusing on Internet VPNs, let’s\n

There are countless ways for an enterprise\n

For example, private WAN technologies such\n

to connect to a service provider’s Internet\ninfrastructure.

Although the leased line or MPLS VPN itself\n

means to access the public network that is\nthe Internet.

In addition, technologies such as CATV and\n

for home Internet access, can also be used\nby an enterprise.

I’m repeating myself, but for both enterprise\n

ethernet connections are growing in popularity\n

But now let’s briefly look at two Internet\n

First let’s look at DSL, which stands for\n

DSL provides internet connectivity to customers\n

line that is already installed in most homes.

So, this is very convenient for both the service\n

Now, there is one extra device here that I\n

except for a brief mention in the previous\nvideo.

A modem, which stands for modulator-demodulator,\n

suitable to be sent over the phone lines.

The modem might be a separate device, as in\n

This connects the network to the service provider\n

But there is another common kind of communication\n

Cable Internet is a similar concept to DSL,\n

But it provides Internet access via the same\n

So, just like DSL, it takes advantage of already-installed\n

Like DSL, a cable modem is required to convert\n

And also like a DSL modem, the cable modem\n

Now, for a home user, having one connection\n

It’s a bit annoying if you lose Internet\n

However, for many companies Internet access\n

So, it’s best to have redundant Internet\n

First, if you have 1 connection to 1 ISP,\n

This is like a standard home Internet connection.

For an enterprise, this is not ideal, because\n

If you have 2 connections to that same ISP,\n

This provides some redundancy, but still not\nideal.

If you have 1 connection to each of 2 ISPs,\n

This improves the redundancy because if something\n

And finally there is dual multihomed, 2 connections\n

This provides the most redundancy.

Depending on the company, this might not be\n

So, make sure you know these four terms.

Single homed, dual homed, multihomed, and\ndual multihomed.

Okay, that’s enough about Internet access\nfor now.

Let’s move on to the final topic, Internet\nVPNs.

Private WAN services such as leased lines\n

traffic is separated by using dedicated physical\n

tags that separate the traffic.

However, when using the Internet as a WAN\n

So, to provide secure communications over\n

We will cover two kinds of Internet VPNs.

First, site-to-site VPNs using IPsec, and\n

So let’s get right into the first one, site-to-site\n

A site-to-site VPN is a VPN between two devices\n

In the diagram below office A and office B\n

will use a site-to-site VPN between them so\n

In a site-to-site VPN, a VPN tunnel is created\n

original IP packet with a VPN header and a\nnew IP header.

When using IPsec, the original packet is encrypted\n

This is what makes IPsec secure.

So, the router will take the original packet,\n

an IPsec VPN header and a new IP header, and\n

Let me demonstrate that process in the diagram.

We have configured an IPsec tunnel between\nthese two routers.

The PC at office A wants to send traffic to\n

unencrypted data to its default gateway, the\nrouter.

The router encrypts the data, and adds a VPN\n

Then the encrypted data in the new packet\n

The receiving router decrypts the data, and\n

That’s a very basic overview of how IPsec\nVPNs work.

When the router receives a packet that is\n

packet and a session key, also called an encryption\n

Then the sending device, the router, encapsulates\n

The new packet is then sent to the device\n

This device then decrypts the data to get\n

Of course, this is an oversimplification of\n

Now, note that in a site-to-site VPN a tunnel\n

for example the two routers connected to the\nInternet.

All other devices in each site don’t need\n

They can send unencrypted data to their site’s\n

it in the tunnel as described above.

The next type of VPN we will look at, remote\n

Before looking at remote-access VPNs, I want\n

First, IPsec doesn’t support broadcast and\n

This means that routing protocols such as\n

routing protocols rely on multicast traffic.

We can solve this with GRE over IPsec, which\nwe’ll look at next.

Another potential problem for large networks\n

between many sites is a labor-intensive task.

It takes a lot of time and careful planning\n

This problem can be solved with Cisco’s\nDMVPN.

Let’s briefly look at each of the above\nsolutions.

GRE, which stands for Generic Routing Encapsulation,\n

encrypt the original packet, so it is not\nsecure.

However it has the advantage of being able\n

as well as broadcast and multicast messages.

So, to get the flexibility of GRE with the\n

The original packet will be encapsulated by\n

the GRE packet will be encrypted and encapsulated\n

So, here’s the original IP packet.

A GRE header and new IP header are added to\nit.

Then this new packet is encrypted, and an\n

We have combined GRE with IPsec.

That’s all I’ll say about GRE over IPsec\nfor now.

You don’t need to know more than this for\nthe CCNA.

Now, regarding the problem of configuring\n

DMVPN, which stands for Dynamic Multipoint\n

routers to dynamically create a full mesh\n

configure every single tunnel.

This is a major oversimplification, but let\n

First, you configure IPsec tunnels to a hub\nsite.

Notice that the router at the top is the hub,\n

to that hub router, but not to the other spoke\nrouters.

Then, the hub router gives each router information\n

So, we only configured hub-and-spoke tunnels,\n

of IPsec tunnels on their own.

To summarize, DMVPN provides the configuration\n

router only needs one tunnel to be configured,\n

because spoke routers can communicate directly\n

Some companies might want all traffic to flow\n

can control the traffic, but other companies\n

communication that a full mesh provides.

Now let’s move on to the other major type\n

Whereas site-to-site VPNs are used to make\n

over the Internet, remote VPNs are used to\n

to access the company’s internal resources\n

Remote-access VPNs typically use TLS, transport\n

VPNs which typically use IPsec.

TLS is also what provides security for HTTPS,\nHTTP secure.

It was formerly known as SSL, Secure Sockets\n

renamed to TLS when it was standardized by\nthe IETF.

VPN client software, for example Cisco AnyConnect,\n

laptops that employees use to work from home.

If you work for a company from home, your\n

These end devices then form secure tunnels\n

This allows the end users to securely access\n

without being directly connected to the company\nnetwork.

Here’s a diagram to help you visualize it.

The end devices on the left want to access\n

They all have Cisco AnyConnect installed,\n

So, the devices each form a TLS VPN tunnel\n

securely communicate with the company’s\n

Note that, just like IPsec, TLS involves encrypting\n

for the sake of time we’ll skip over those\ndetails.

So, finally let’s briefly compare site-to-site\n

Site-to-site VPNs typically use IPsec, and\n

Both of them are protocols that you don’t\n

but you should definitely know their names\n

Site-to-site VPNs provide service to many\n

One IPsec tunnel between two routers or firewalls\n

the sites they are connecting.

On the other hand, remote-access VPNs provide\n

Instead of connecting two sites together,\n

Site-to-site VPNs are typically used to permanently\n

And remote-access VPNs are typically used\n

that want to securely access company resources\n

These two types of VPNs are specifically mentioned\n

know the differences between them.

Okay, before moving on to the quiz let’s\nreview what we covered.

This video was just a shallow look at various\n

Each topic in this video is very important\n

you’re just starting your journey you don’t\n

and the CCNA exam doesn’t expect you to\nknow them all.

Wide Area Networks are used to connect geographically\n

For example, to connect two offices together\n

Then, we looked at leased lines.

Leased lines are dedicated physical connections\n

For many reasons they are being replaced by\n

MPLS allows enterprises to form WANs over\n

Although the traffic of many different customers\n

the label-switching aspect of MPLS allows\n

If you want to really learn how MPLS works,\n

Then we looked at a few ways to connect to\n

And finally Internet VPNs, specifically site-to-site\n

These provide secure connectivity over the\n

Make sure to watch until the end of the quiz\n

ExSim for CCNA, the best practice exams for\nthe CCNA.

Okay, let’s go to quiz question 1.

Which of the following leased line standards\n

Pause the video now to select the correct\nanswer.

Here’s that wikipedia chart again.

I doubt that you’ll have to memorize all\n

hurt to be familiar with them.

Okay, let’s go to quiz question 2.

Jeremy’s IT Lab Professional IT Training\n

Which of the following routers does NOT run\nMPLS?

Pause the video to select the correct answer.

In MPLS, PE, provider edge, and P, provider\n

However, there is no need for the CE, customer\n

Which of the following MPLS VPN types allows\n

Pause the video to select the best answer.

Okay, the answer is A, Layer 2 MPLS VPN.

Although MPLS is sometimes called a Layer\n

between the Layer 2 and Layer 3 headers, there\n

And in Layer 3 MPLS VPNs, the OSPF peerings\n

In a Layer 2 MPLS VPN, the entire service\n

and it is as if the service provider network\n

Which of the following Internet access technologies\n

Pause the video to select the best answer.

Digital Subscriber Line provides connectivity\n

over phone lines, which are typically already\n

As a bonus, it allows users to access the\n

which was not allowed in previous technologies\n

Which of the following protocols can be used\n

flexibility by allowing multicast traffic\n

Pause the video now to select the best answer.

Generic Routing Encapsulation is more flexible\n

well as broadcast packets to be encapsulated\n

However, GRE isn’t secure because it doesn’t\n

So, the GRE packet can be encrypted and then\n

Okay, that’s all for the quiz.

Now let’s take a look at a bonus question\n