Introduction to SD-WAN

This topic is to discuss the following lesson:

Hi Renee,
Would this SD-WAN explanation be enough to pass the CCNP exam?


Hello Dan

According to Cisco’s blueprint of the CCNP ENCOR exam topics, SD_WAN appears in the following topics:

1.4 Explain the working principles of the Cisco SD-WAN solution
1.4.a SD-WAN control and data planes elements
1.4.b Traditional WAN and SD-WAN solutions

Because the blueprint says “explain the working principles”, this usually means that you must know what the technology is and how it works at a theoretical level. This lesson sufficiently describes this, including the subsections which include the control and data planes, as well as SD-WAN solutions. The various components, as well as packages that Cisco provides for such services are also described in detail.

Based on the blueprint, as well as on Cisco’s certification guides, this lesson covers all of the stated concepts for SD-WAN.

I hope this has been helpful!


Can someone explain to me what is the purpose of a TLOC and TLOC extensions? I’m confused between the two and why do we need them.

Hello Conrad

For context, and for our other readers, let me just mention that Cisco acquired Viptela Inc., an SD-WAN company based in San Jose in 2017. Cisco’s SD-WAN solutions are based on Viptela’s technology, and terminology, which includes the concept of a Transport Location or TLOC.

Taking a step back, we can say that Cisco’s SD-WAN solution is based upon the use of the Overlay Management Protocol (OMP) which is a routing protocol similar to BGP, which is used to manage the SD-WAN overlay network, which is also referred to as the SD-WAN fabric. This fabric is the software defined overlay that runs on top of standard network transport services and infrastructure such as MPLS networks, or the public Internet.

Getting closer to your question :wink: a TLOC is used to define a specific interface in the overlay network of an SDN implementation. It is actually used to tie an OMP route to a physical location. It is the only entity of the OMP routing domain, that operates on the overlay, that is “visible” to the underlay network. As such it must be reachable via routing in the underlying network. A TLOC contains various attributes, including IP address, color (an attribute that identifies the TLOC type) and Domain ID to name a few. In other words, a TLOC is a transport attachment point for the overlay tunnel which is used by OMP for routing.

TLOC extensions are used when you want to achieve redundancy across multiple topologies allowing a dual homed design. Similar in functionality to protocols such as VRRP, TLOC allows for redundant connectivity without the need for the redundant devices to be directly connected, such as is the case with VRRP and HRRP for example. An excellent example of how this works can be found on pages 9 and 10 of the following Cisco white paper.

For more detailed information about TLOCs, and SD-WAN in general, the following Cisco documentation is also very helpful.

I hope this has been helpful!



Thank you Laz for the explanation

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Hi Laz and Rene:

Do you have or intent to post more details on SDWAN in particular? Specifically, how to bring up the control plane, underlay / dataplane. How devices communicate with the controllers etc more deeper than the ENCOR exam’s blue print? The reason for the ask is, I did go through the documents, but most of them are confusing for deployment. I see a lot of traction in SDWAN. Let us know if anything is in pipeline from networklessons on this. If not I request to consider the same.

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Hello Rama,

I probably will, there is a lot of demand for SD-WAN and I get quite some requests for this.


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Hi to all,

I want to implement SD_WAN Laboratory i have notice on normal pc it’s not possible about the memory ecc ecc
I want know how make practises with this technology


Hello Ugo

The SD-WAN solution that Cisco uses is Viptela. This is a company that was acquired by Cisco in 2017 and has been rebranded to Cisco SD-WAN. Viptela/Cisco SD-WAN can fully run on a VM and can be emulated within a GNS3 environment. Take a look at this GNS3 thread that discusses how this can be done.

You can get an overview of the operation of Cisco SD-WAN in the related section of this lesson:

I hope this has been helpful!


very very thanks for your help

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Hello … any news about explaining SD-WAN with LABs

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Hello Safwan

Because CCNP certifications don’t require anything beyond the theory, there are no labs for SD-WAN in the content. For CCIE Rene is in the process of creating a list of lab equipment and options which will include SD-WAN. You can find out more info about that at the following post:

In other words, SD-WAN labs coming soon… :sunglasses:

I hope this has been helpful!

Where is the configuration part

Hello Sims

Take a look at this post:

I hope this has been helpful!


I want to know if the course CCIE has all the topics to pass the lab. because i saw in the part Unit 2 (Software Defined Infrastructure), i don’t see the topics for Cisco SD-WAN.

Thanks a lot.
Best regards,

Hello Edmond

To answer your question, take a look at this post:

I hope this has been helpful!



Hi Rene,

I have just two questions for you.

  1. When we can expect that you will ready with SD WAN Viptela LAB Setup and can I practice that LAB?
  2. Can I have one details on good SD WAN Viptela Rack Rental for Practice.

Thank you

Hi Team, from the logs of one of the vEdge, what should have caused the disconnection of this site?
It seems everynight this vEdge was unreachable from the vManage.

Thank You Team

Hello Dan

Without knowing more about the topology and the setup, it looks like the BGP peering has been torn down. Since there is a hold-time expiry with neighbour and then less than a minute later there’s another expiry with neighbour as well… Could there be a network connectivity issue?

I hope this has been helpful!