300-415 Question 121
Select 3A network engineer is deploying a Cisco SD-WAN solution for a branch office with two WAN circuits: an MPLS circuit and an internet broadband connection. To ensure high availability and redundancy, the engineer decides to extend the TLOCs from one edge device to another using a cross-connect. Which of the following requirements must be met to successfully configure TLOC-extension in this scenario?
- A
Both edge devices must belong to the same site ID.
- B
The MPLS and internet circuits must terminate on different edge devices.
- C
A dedicated physical link must connect the two edge devices for TLOC-extension.
- D
The TLOC-extension configuration must be applied to both edge devices.
- E
Both edge devices must have identical system IP addresses.
Show answer and explanation
Correct answers: A, C, D
Explanation
TLOC-extension is a feature used in Cisco SD-WAN to extend Transport Locators (TLOCs) from one WAN Edge device to another, enabling high availability and redundancy when circuits terminate on different devices. For proper configuration, both devices must belong to the same site ID, a dedicated physical link must connect them, and the TLOC-extension configuration must be applied to both devices. Unique system IP addresses are required for each device, and while TLOC-extension is typically used when circuits terminate on different devices, this scenario highlights its configuration requirements.
- A. Correct.
Correct. For TLOC-extension to function properly, both edge devices must belong to the same site ID, as this ensures they are treated as part of the same logical site within the SD-WAN fabric.
- B. Incorrect.
Incorrect. While TLOC-extension is typically used when circuits terminate on different edge devices, this is not a strict requirement. The circuits could terminate on the same edge device, but TLOC-extension is often deployed to provide redundancy across devices.
- C. Correct.
Correct. A dedicated physical link is required between the two edge devices to enable TLOC-extension, as this link facilitates the exchange of TLOC information and traffic forwarding between the devices.
- D. Correct.
Correct. The TLOC-extension configuration must be applied to both edge devices to enable proper functionality and ensure traffic can be extended between their TLOCs.
- E. Incorrect.
Incorrect. Both edge devices must have unique system IP addresses in the SD-WAN fabric to avoid conflicts. Identical system IPs would disrupt the operation of the SD-WAN solution.