All language subtitles for Free-CCNA-Intro-to-Network-Automation-Day-59-CCNA-200-301-Complete-Course_en

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In this video we’ll look at network automation.

Actually this will be a series of videos covering\n

and this first video will be an introduction\n

we will cover in more detail in later videos.

Automation is section 6.0 of the CCNA exam\n

Read these exam topics carefully.

They state that you have to be able to explain,\n

However you don’t actually have to be able\n

Cisco just wants you to understand various\n

the actual hands-on automation is left for\n

above, as well as the DevNet certification\ntrack.

In this video we’ll mostly be looking at\n

a general overview of network automation and\nits benefits.

First I’ll give a quick overview of why\n

I’ll then explain the logical planes of\n

Maybe you’ve heard of these before, but\nmaybe you haven’t.

I’ll explain what they are, because they\n

While introducing SDN, I’ll also introduce\n

As I said, this video will be an introduction\n

them in greater detail in the next few videos.

And make sure to watch until the end of the\n

Software’s ExSim for CCNA, the best practice\nexams for the CCNA.

So let’s look at network automation.

Previous versions of the CCNA focused on the\n

Actually, the current version does too, but\n

of various topics related to network automation,\n

In the traditional model, engineers manage\n

Telnet connections are possible too of course,\n

Some devices support a GUI also.

But the main point here is that devices are\n

So, let’s say your company wants to add\n

You connect to R1 using SSH, configure the\n

And every one of the hundreds of routers in\n

So what are some downsides to managing a network\nlike this?

First, typos and other small mistakes are\ncommon.

I’m sure that as you’ve been doing practice\n

Sometimes you realize it immediately and fix\n

of time troubleshooting to find that the problem\n

It is also time consuming and can be very\n

Repetitive tasks can be automated and performed\n

And here’s another issue that might be harder\n

It is difficult to ensure that all devices\n

An organization will usually have standard\n

their devices, and it’s important to ensure\n

However, as individual network engineers make\n

can start to drift away from the standard.

This can cause issues down the line, for example\n

the devices don’t all have similar configurations.

Of course, when I talk about the disadvantages\n

it in comparison to network management and\n

Network automation offers many key benefits.

First, human error is reduced, for example\ntypos.

Instead of a network engineer directly logging\n

Networks become much more scalable.

New network deployments, network-wide changes,\n

Also, network-wide policy compliance can be\n

have the proper standard configurations, all\n

And the improved efficiency of network operations\n

Each task requires fewer man-hours, and engineers\n

For example, in the same situation as before\n

to hundreds of routers, instead of logging\n

a loopback interface, which could take hours\n

task and make the proper configurations in\n

Note that there are various tools and methods\n

SDN, Ansible, Puppet, Python scripts, and\nmany more.

Throughout these videos I’ll introduce multiple\n

video let’s focus on the concept of SDN,\n

To understand SDN, you have to understand\n

Here you can see two simple questions.

A router forwards messages between networks\n

And a switch forwards messages within a LAN\n

Okay, but is that all that routers and switches\ndo?

A router also uses a routing protocol like\n

routers and build a routing table.

It also uses ARP to build an ARP table, mapping\n

For example, it would use ARP to learn the\n

It also uses Syslog to keep logs of events\nthat occur.

We are also able to use SSH to connect to\n

And of course there are many more things that\n

A switch uses STP to ensure that there are\n

It builds a MAC address table by examining\n

Like a router, it also uses protocols like\nSyslog and SSH.

Those are just some examples, there are many\n

And if it’s a Layer 3 switch, it can have\n

OSPF to build a routing table.

Anyway, the point is that routers and switches\n

They don’t just forward messages at Layer\n2 or Layer 3.

And these various functions of network devices\n

Typically we divide the functions into three\nplanes.

The data plane, the control plane, and the\nmanagement plane.

Let’s take a look at the functions of each\nplane.

First let’s look at the data plane.

All tasks involved in forwarding user data\n

So, this is what you usually think of a router\n

A router receives a message, looks for the\n

table, and forwards it out of the appropriate\n

Or to the destination, if its directly connected.

It also de-encapsulates the original Layer\n

destined for the next hop’s MAC address.

All of these functions are part of the data\nplane.

Likewise, a switch receives a message, looks\n

it out of the appropriate interface.

Or it floods it out of all interfaces when\nappropriate.

This also includes functions like adding or\n

Also, functions like NAT, which changes the\n

forwarding, is part of the data plane.

It’s part of the process of forwarding a\nmessage.

Also, deciding to forward or discard a message\n

Note that another name for the data plane\n

Here’s an example with two routers.

R1 receives a packet, and the data plane processes\n

And then R2’s data plane processes the packet\n

In this instance R2 discarded a packet from\nR1.

Perhaps an ACL configured on R2’s interface\n

Anyway, that’s an action of the data plane.

Next, let’s look at the control plane.

How does a device’s data plane make its\nforwarding decisions?

How can a router choose which interface to\n

How does it know what the next hop is?

Devices use things like their routing table,\n

things, to make these forwarding decisions.

Functions that build these tables, and other\n

So, the control plane controls what the data\n

The functions of the control plane are considered\noverhead work.

Let me explain that statement with some examples.

The OSPF protocol itself doesn’t forward\n

plane about how packets should be forwarded.

Likewise, STP itself isn’t directly involved\n

informs the data plane about which interfaces\n

One more example, ARP messages aren’t user\n

which is used in the process of forwarding\ndata.

So, I think you can get an idea of what is\n

Let me demonstrate again with a diagram.

R1 and R2 communicate using OSPF, and this\n

These routing tables control the actions of\n

forwarding of data packets takes place.

So, in traditional networking the data plane\n

Each device has its own data plane and its\n

It’s not one centralized control plane that\n

This is different than in software-defined\n

Finally let’s look at the management plane.

Like the control plane, the management plane\n

However, the management plane doesn’t directly\n

Instead, it consists of protocols that are\n

For example, SSH and Telnet, which are used\n

Or Syslog, which is used to keep logs of events\n

Also SNMP, which is mainly used to monitor\n

NTP is another example, which is used to maintain\n

There’s not much else to say about the management\n

And here’s an example of management plane\noperations.

A network engineer uses SSH to connect to\n

For example, perhaps he configured OSPF and\n

using OSPF to exchange routing information.

This then determines how packets are forwarded\n

And that’s a basic summary of how these\n

The data plane is really the essential one,\n

We want them to forward messages.

But in order for the data plane to do its\n

Before wrapping up this section I want to\n

The operations of the management plane and\n

However, this is not desirable for data plane\n

So, instead a specialized hardware ASIC, application-specific\n

These are chips built for specific purposes,\n

Here is a picture from Wikipedia of some ASICs.

Let me use a switch as an example to demonstrate\nhow this works.

When a frame is received, the ASIC, not the\n

Remember, this is a specialized chip designed\n

Also, the MAC address table is stored in a\n

TCAM allows for very fast lookups of MAC addresses.

Definitely remember that term, TCAM.

Also note that another common name for the\n

So, the ASIC feeds the destination MAC address\n

the matching MAC address table entry, and\n

Note that modern routers also use a similar\n

for forwarding logic and the necessary tables\nstored in TCAM.

So, to summarize this: when a device receives\n

the device itself, it will be processed in\nthe CPU.

However when a device receives data traffic\n

processed by the ASIC for maximum speed.

Note that not all data plane traffic is processed\n

but for now I won’t go any further into\nthis topic.

We can leave that for CCNP-level studies.

So, the reason I spent all of that time going\n

to understanding the next concept, software-defined\nnetworking.

SDN is an approach to networking that centralizes\n

Now, this isn’t a new concept for you.

You should be familiar with it already from\n

When using a WLC, many functions are removed\n

so the APs role primarily becomes just forwarding\ntraffic.

Note that SDN can also be called software-defined\n

As I said earlier, traditional control planes\n

each router runs OSPF, shares routing information\n

calculates its preferred routes to each destination.

An SDN controller centralizes control plane\n

Note that that is just an example, and how\n

There are many different SDN solutions available,\n

devices varies in each solution.

A controller can interact programmatically\n

APIs are application programming interfaces.

I’m sure that many of you have heard of\n

I will dedicate a video to APIs later, so\n

I will briefly introduce them in this video.

So, here’s our traditional architecture.

Note that for the purpose of this discussion\n

We’re just focusing on the functions of\nthe control plane.

Now I’ve removed the control planes from\nR1 and R2.

Then, we have a controller, an application\n

plane of the network is centralized here.

Instead of R1 and R2 using OSPF to exchange\n

the controller communicates with R1 and R2\n

So, instead of the control plane being distributed,\n

it is centralized in the controller.

I’m only showing two routers here, but this\n

and this controller would operate the control\n

The communication between the devices and\n

the southbound interface, SBI.

It’s called southbound because in diagrams\n

the network devices on the bottom, the south.

Note that this term doesn’t refer to any\n

a software interface that is used to allow\n

Now, before moving on to the next slide I\n

shows a totally centralized control plane,\n

Some of them centralize the entire control\n

functions of the control plane.

So let’s look at SBIs, southbound interfaces.

The SBI is used for communications between\n

In the diagram, R1 and R2 are controlled by\n

The SBI typically consists of a communication\n

As I said before we’ll cover APIs in another\nvideo.

But basically, they are used to facilitate\n

The controller is a program, and the network\n

So, data is exchanged between the controller\n

API on the network device can allow the controller\n

data plane tables that are used to forward\npackets, etc.

APIs play a big role in automating networking\n

Here are some examples of south bound interfaces.

OpenFlow, Cisco OpFlex, Cisco onePK, and NETCONF.

I will cover some of these in more detail\n

memorizing their names and remembering that\n

controller to communicate with the devices\nit controls.

In addition to the southbound interface, there\n

So, to review, using the SBI the controller\n

gathers information about them.

For example, which devices are in the network,\n

Which interfaces are available on the device,\n

etc, and much more information.

That’s what the SBI is used for.

The northbound interface, NBI, is what allows\n

the data it gathers about the network, program\n

We can tell the controller to make a change,\n

So, here we have an app, and it will use the\n

I explained the name southbound interface\n

is called the northbound interface.

A REST API is used on the controller as an\n

REST stands for representational state transfer,\nby the way.

I’ll explain REST APIs more in the API video.

Just note that REST isn’t a specific API,\nbut a type of API.

So, there is an interface on the controller.

As I mentioned earlier, this isn’t a physical\n

it’s code that facilitates communication\n

So, the app sends a GET message to the API\n

The controller will reply with the requested\n

Perhaps you’ve heard of JSON or XML before.

I’ll make a separate video explaining them,\n

standard formats for structuring data.

It makes it much easier for programs to use\n

format that is easy to interact with.

Okay, that was a basic overview of the main\n

Before wrapping up the video, let’s spend\n

So, we’ve been looking at SDN a lot, but\n

For example, scripts can be written, for example\n

The script can enable your computer to SSH\n

you want, perhaps configuring VLANs on many\nswitches.

Also, Python with good use of regular expressions\n

information about the network devices.

If you don’t know what regular expressions\n

are just ways of searching for patterns in\ntext.

Look at this SHOW command for example, SHOW\nINTERFACES.

This is in a human-readable format, it’s\n

and get what information we need.

For example, if you want to know the bandwidth\n

kilobits per second, so 1 gig.

You can write a script that does the same,\n

command, and then parse through the output\n

However, the robust and centralized data collected\n

The controller collects robust information\n

Also the northbound APIs allow apps to access\n

to understand, formats such as JSON or XML.

No need to write scripts to parse through\n

Also, having this centralized data facilitates\n

information from individual devices and having\n

SDN tools provide the benefits of automation\n

This also means that you don’t need expertise\n

Many of them are very easy to use even for\n

However, APIs allow third-party applications\n

be very powerful if you’re able to create\nyour own apps.

To summarize, although SDN and automation\n

of network automation, the SDN architecture\n

tasks in the network via the SDN controller\nand APIs.

In this video we covered various topics related\n

We didn’t really go in depth, but that’s\nfine.

This is an introductory video to the automation\n

videos in total, so we have plenty of time\nto learn the details.

But network automation is a paradigm shift\n

of digging into the details right away I think\n

In the next video we’ll look at data serialization,\n

This is an important topic because it puts\n

Okay, let’s go into the quiz for today,\n

quiz for a bonus question from Boson Software’s\n

Okay, let’s go to quiz question 1.

Which of the following are benefits of network\nautomation?

Pause the video now to select the best answers,\nselect two.

Okay, the answers are A, reduced human error,\n

Because automation means network engineers\n

commands into the CLI, human error such as\ntypos can be reduced.

Also, tasks can be achieved in a much shorter\n

Which of the following are SBIs?

Pause the video now to select the best answers.

Okay, the answers are C, OpenFlow and D, OpFlex.

Other examples of SBIs given in this video\n

We’ll cover some of them in detail later,\n

Which of the following network functions would\n

Pause the video now to select the best answer.

Okay, the answer is A, calculating routes.

B, C, and D are all data plane functions,\n

A, calculating routes, is a function of the\n

What is the purpose of the SBI in SDN architecture?

Pause the video now to select the best answer.

Okay, the answer is C, to facilitate data\n

For review, here’s that diagram again showing\n

Regarding option B, it is the northbound interface,\n

the controller and apps, not the SBI.

Which of the logical planes of networking\n

Pause the video now to select the best answer.

Okay, the answer is B, management plane.

NTP is used to provide accurate time for the\ndevice.

It is not involved in the forwarding of messages,\n

Instead, it operates at the management plane.

Okay, that’s all for the quiz.

Now let’s look at a bonus question in Boson\n