Virtual Extensible LAN - CompTIA Network+ N10-009 - 1.8

Summary

The script discusses the challenges of managing applications across multiple data centers with varying IP addressing schemes and connectivity types. It introduces Data Center Interconnection (DCI) and Virtual Extensible LAN (VXLAN) as solutions. VXLAN, an improvement over VLANs, supports up to 16 million virtual networks and enables seamless connectivity over layer 3 networks. The script illustrates how VXLAN tunnels encapsulate and transport data between data centers, allowing virtual machines to operate as if they are on the same network despite being in different locations.

Takeaways

• 🌐 **Data Center Interconnection (DCI)**: Organizations distribute applications and servers across various data centers, necessitating seamless connectivity between them.
• 🌟 **Challenges with IP Addressing**: Different data centers may have distinct IP addressing schemes, complicating connectivity.
• 🌉 **Cloud-based Distribution**: Applications are often distributed across multiple data centers, which might be located worldwide.
• 📡 **Connectivity Variance**: Data centers can have different types of connectivity, from high-bandwidth fiber to copper-based connections.
• 🛠️ **Abstraction of Network Details**: Applications should operate without concern for the underlying network infrastructure or IP schemes.
• 🔄 **Virtual Extensible LAN (VXLAN)**: VXLAN is a technology designed to support thousands of customers using the same data centers globally.
• 📏 **VLAN Limitations**: VLANs are limited to around 4,000 virtual networks and are non-routable due to their layer 2 confinement.
• 🚀 **VXLAN Capabilities**: VXLAN can support up to 16 million virtual networks and allows for routing over a layer 3 network.
• 🌉 **VXLAN Tunnel Endpoints (VTEPs)**: VTEPs are used to create VXLAN tunnels, identified by IP addresses and VNIs (VXLAN Network Identifiers).
• 🔗 **VXLAN Tunneling**: VXLAN tunnels encapsulate and transport data across an IP network, making it appear as if virtual machines are directly connected.

Q & A

What is Data Center Interconnection (DCI)?

Data Center Interconnection (DCI) is a method to connect different data centers seamlessly with each other, allowing for the distribution of applications and resources across multiple locations.

Why is it important to have a consistent IP addressing scheme across data centers?

A consistent IP addressing scheme across data centers is important to ensure that applications can move between data centers without issues related to connectivity or addressing conflicts.

What challenges arise when devices are located in different data centers with different connectivity types?

Challenges include managing different IP addressing schemes and varying network infrastructures, which can complicate the operation of applications that need to communicate across these centers.

How does the cloud facilitate the distribution of applications across data centers?

The cloud allows applications to be distributed across multiple data centers, which may be located in different geographical locations, providing flexibility and scalability.

What is a Virtual Extensible LAN (VXLAN) and how does it differ from VLANs?

VXLAN is a network technology that supports thousands of different customers using the same data centers across the world. It differs from VLANs by supporting up to 16 million virtual networks and allowing them to be connected over a layer 3 network, making them routable over the existing public internet.

What is the limitation of VLANs in the context of data center networking?

VLANs are limited to around 4,000 different virtual networks and are confined to layer 2, which restricts their scalability and routability.

How does VXLAN enable the routing of virtual networks over the existing public internet?

VXLAN encapsulates the original Ethernet frame within a VXLAN header that sits inside a UDP header, in an IP header, allowing it to be routed over a layer 3 network.

What is a VXLAN tunnel endpoint (VTEP) and what is its role?

A VXLAN tunnel endpoint (VTEP) is a device, such as a switch, that contains a VXLAN tunnel and is responsible for encapsulating and decapsulating traffic between virtual networks across different data centers.

What is a VXLAN Network Identifier (VNI) and how does it help in connecting different data centers?

A VXLAN Network Identifier (VNI) is a unique identifier used to segment different VXLAN networks. It helps in connecting corresponding VNIs across different data centers through VXLAN tunnels.

Can you explain the process of encapsulation and decapsulation in the context of VXLAN?

Encapsulation in VXLAN involves wrapping the original Ethernet frame within a VXLAN header for transport across a tunnel. Decapsulation is the process of removing this VXLAN header at the destination, restoring the original frame for local network use.

How does VXLAN help in creating a seamless connection between virtual machines in different data centers?

VXLAN allows virtual machines in different data centers to communicate as if they are on the same local network by encapsulating and routing their traffic through VXLAN tunnels, making the connection appear seamless.

Outlines

00:00

🌐 Data Center Interconnection and VXLAN

The paragraph discusses the concept of Data Center Interconnection (DCI) and its importance in connecting multiple data centers seamlessly. It highlights the challenges of IP addressing and connectivity differences across various data centers. The paragraph introduces Virtual Extensible LAN (VXLAN) as a solution to these challenges, emphasizing its ability to support up to 16 million virtual networks over a layer 3 network, unlike VLANs which are limited to 4,000 and are non-routable. A scenario involving two data centers with virtual machines and VXLAN tunnel endpoints is described to illustrate how VXLAN enables the connection of virtual machines across different data centers.

05:00

🔗 Seamless Connectivity with VXLAN

This paragraph continues the discussion on VXLAN, explaining how it creates a seamless connection between virtual machines in different data centers. It describes the process of encapsulating an original Ethernet frame within a VXLAN header, which is then sent through a VXLAN tunnel over an existing IP network. Upon reaching the destination, the frame is decapsulated, making the virtual machines appear as if they are directly connected despite being in separate data centers.

Keywords

💡Data Center Interconnection (DCI)

DCI refers to the practice of linking multiple data centers together to allow seamless data transfer and communication. In the context of the video, DCI is crucial for organizations that distribute their applications and servers across various data centers. It enables them to treat these centers as a unified infrastructure rather than as isolated units. The video mentions that DCI allows for the connection of data centers 'seamlessly with each other', highlighting its importance in maintaining the integrity and efficiency of distributed IT systems.

💡IP Addressing

IP addressing is the method by which individual devices on a network are identified and located through unique numerical labels. The video discusses the challenges that arise when devices in different data centers have different IP addressing schemes. This can complicate connectivity and network management. The script mentions how some data centers might have 'one IP addressing scheme for data center A and a completely different IP addressing scheme for data center B', emphasizing the need for a solution that abstracts away these differences.

💡Connectivity

Connectivity in this context refers to the ability of devices in different data centers to communicate with each other. The video highlights that connectivity can vary greatly between data centers, with some having high bandwidth and fiber connectivity, while others might rely on less robust connections like metro ethernet or copper-based networks. The main theme of the video is to achieve a state where 'the applications that are residing in these data centers shouldn't have to worry about connectivity types', which underscores the importance of a consistent and reliable connection method across different centers.

💡Virtual Extensible LAN (VXLAN)

VXLAN is a network technology that allows for the creation of virtual networks that can span across different physical networks. It is introduced in the video as a solution to the problem of connecting multiple data centers with different IP schemes and network infrastructures. VXLAN enables the support of 'up to 16 million virtual networks' over a layer 3 network, which is a significant advantage over traditional VLANs that are limited to around 4,000 networks and are non-routable. This technology is central to the video's narrative as it provides a scalable and flexible way to interconnect data centers.

💡Virtual Local Area Network (VLAN)

A VLAN is a logical grouping of devices on a network that treats them as if they are on the same local network, even if they are physically located on different network segments. The video mentions VLANs as a precursor to VXLAN, designed to span 'across multiple switches at layer 2'. However, VLANs have limitations such as the support for only around 4,000 virtual networks and their non-routable nature at layer 2, which makes them insufficient for the large-scale virtual environments discussed in the script.

💡Virtual Machines (VMs)

Virtual machines are software implementations of physical machines that run applications or processes. In the video, VMs are used to illustrate the concept of virtualization within data centers. The script describes a scenario with 'a virtualization server... with a virtual switch and three separate virtual machines A1, B1, and C1'. VMs are a key component in the discussion because they represent the applications that need to be connected across different data centers without any issues related to IP addressing or network infrastructure.

💡VXLAN Tunnel Endpoint (VTEP)

A VTEP is a component in a VXLAN network that is responsible for encapsulating and de-encapsulating traffic. The video describes how VTEPs with different IP addresses, such as '1.1.1.1' and '2.2.2.2', are used in different data centers to facilitate the creation of VXLAN tunnels. VTEPs play a critical role in the video's explanation of how VXLAN works, as they are the points through which traffic is sent and received across the VXLAN network, effectively connecting different data centers.

💡VXLAN Network Identifier (VNI)

The VNI is a unique identifier used in VXLAN to differentiate between different virtual networks. The video mentions VNIs such as 'VNI 2000, VNI 3000, and VNI 4000' in the context of connecting specific virtual networks in different data centers. VNIs are essential for the operation of VXLAN as they allow for the multiplexing of different virtual networks over a single physical network, which is a key feature highlighted in the video.

💡Encapsulation

Encapsulation in networking refers to the process of wrapping data in a protocol header before it is transmitted across a network. The video uses encapsulation as a mechanism within VXLAN to send data from one data center to another. It describes how the 'original frame... is encapsulated within a VXLAN header that sits inside a UDP header, in an IP header in an ethernet frame'. This process is fundamental to how VXLAN operates, allowing data to be transported across different networks while maintaining the integrity and addressing of the original data.

💡Decapsulation

Decapsulation is the reverse process of encapsulation, where the protocol headers are removed from the data as it reaches its destination. The video mentions decapsulation in the context of data arriving at a data center through a VXLAN tunnel, where 'the original ethernet frame is then in the second data center and added to the existing virtualization server'. Decapsulation is crucial for VXLAN as it allows the data to be understood and processed by the receiving virtual machines as if they were on the same local network.

Highlights

Data Center Interconnection (DCI) enables seamless connectivity across multiple data centers.

DCI is crucial for service providers with customers using resources across various data centers worldwide.

Cloud applications may move to any data center location, necessitating consistent connectivity.

IP addressing can vary significantly across different data centers.

Connectivity types can differ widely among data centers, from fiber to copper-based connections.

Applications should operate without concern for connectivity types or IP address schemes.

A virtual extensible LAN (VXLAN) provides a solution for seamless data center connectivity.

VXLAN supports up to 16 million virtual networks, compared to VLANs' limit of around 4,000.

VXLAN allows virtual networks to be connected over a layer 3 network, enabling easy routing over the internet.

VXLAN is designed for large virtual environments and supports applications wherever they are located.

A scenario with two data centers and virtual machines illustrates how VXLAN works.

VXLAN tunnel endpoints (VTEPs) facilitate the connection between different data centers.

VXLAN Network Identifier (VNI) is used to connect corresponding VNIs across data centers.

VXLAN tunnels use existing IP networks to transport encapsulated information.

Encapsulation within a VXLAN header allows for the original frame to be sent through a tunnel.

Decapsulation at the receiving end ensures the original frame is correctly delivered to the virtualization server.

VXLAN enables virtual machines in different data centers to appear as if they are directly connected.

Transcripts

Many organizations will distribute their applications,

their servers, and other devices across many different data

centers.

Instead of treating each of these data centers

as an individual entity, it would be useful

if we could have Data Center Interconnection, or DCI, a way

to connect these different data centers seamlessly

with each other.

If you are a service provider, you

may have 100 or even thousands of customers using resources

that span across multiple data centers located anywhere

in the world.

And of course, we use the cloud to distribute our applications

to multiple data centers that may be located

in many different locations.

And those applications may move at any time

to any of these cloud based data centers.

When you have devices located in different data centers,

however, you may run into situations

where IP addressing is very different across those different

data centers.

There might be one IP addressing scheme

for data center A and a completely different IP

addressing scheme for data center B.

The connectivity to these data centers

may also be very different.

Some data centers may be in a large metropolitan area

with lots of fiber connectivity and large amounts of bandwidth.

Other data centers might connect through metro ethernet

or other types of copper based connectivity.

The applications that are residing in these data centers

shouldn't have to worry about connectivity types, IP address

schemes, or anything else that's unique to that data center.

We should be able to put an application in any location

and that application should work without any type of issue.

We need a way to seamlessly connect these data centers

together without a concern about IP address schemes

or the underlying network infrastructure.

The solution to this problem is a virtual extensible LAN

or VXLAN.

This technology was designed to support thousands

of different customers, all using the same data centers

located across the world.

You may already be familiar with VLANs, or Virtual Local Area

Networks.

VLANs are designed to span across multiple switches

at layer 2 so that you can have different areas of the network

supporting the same IP subnets.

Unfortunately, VLANs have a limited scope because they can

only support around 4,000 different virtual networks

and they are limited to layer 2, which makes them non-routable.

With VXLAN, we can support up to 16 million virtual networks.

And those virtual networks can be connected to each other

over a layer 3 network, which makes

it very easy to route over the existing public internet.

This is designed for the large virtual environments

that we've created and allows us to support our applications

wherever they might be.

Let's take a scenario where we have two data centers.

In one data center, we have a virtualization server.

Inside of that virtualization server

is a virtual switch and three separate virtual machines, A1,

B1, and C1.

In a different data center, we have a similar virtualization

server with its own VSwitch and a virtual machine, A2, B2

and C2.

And in this example, virtual machine A1

is associated with virtual machine A2.

Virtual machine B1 is associated with B2 and virtual machine

C1 is associated with virtual machine C2.

This virtualization server is contained

within a rack that has a top of rack switch

that contains a VXLAN tunnel endpoint.

In one data center that VTEP is numbered 1.1.1.1,

and in a different data center, there's a completely different

IP address for this VTEP of 2.2.2.2.

Notice that both of these VXLAN tunnel endpoints

will support a VXLAN Network Identifier, or VNI.

You can see there is a VNI 2000, a VNI 3000 and VNI 4000 in both

of these data centers.

So the challenge is connecting VNI 2000 in data center with VNI

2000 in another data center, VNI 3000 in one data

center to the other, and VNI 4000 in one data center

to the other.

The way that we would accomplish this

is through the use of a VXLAN tunnel.

This uses an existing IP network to be

able to provide the transportation

and we're able to encapsulate information in one data center,

send it through this tunnel, and decapsulate it on the other end.

Here's how this would work.

We have our original frame in the first data center.

This is a standard ethernet frame

with an ethernet header, an IP header, and the payload

that we would like to send to the other data center.

We're going to encapsulate that original frame within a VXLAN

header that sits inside a UDP header

in an IP header in an ethernet frame.

This information is routed across a VXLAN tunnel, where

on the other side it is decapsulated from the tunnel

and the original ethernet frame is then in the second data

center and added to the existing virtualization server.

This allows us to connect virtual machines into completely

different data centers, but still

have those virtual machines feel that they are both directly

connected to each other.