300-420 · Question #18
Which solution allows overlay VNs to communicate with each other in an SD-WAN Architecture?
The correct answer is A. External fusion routers can be used to map VNs to VRFs and selectively route traffic between. In Cisco SD-WAN (and SD-Access), Virtual Networks (VNs) are logically isolated segments, each mapped to a VRF. By default, traffic cannot cross VN boundaries. External fusion routers (or firewall/service nodes acting as fusion devices) are the Cisco-recommended method to enable…
Question
Which solution allows overlay VNs to communicate with each other in an SD-WAN Architecture?
Options
- AExternal fusion routers can be used to map VNs to VRFs and selectively route traffic between
- BGRE tunneling can be configured between fabric edges to connect one VN to another.
- CSGTs can be used to permit traffic from one VN to another.
- DRoute leaking can be used on the fabric border nodes to inject routes from one VN to another.
How the community answered
(63 responses)- A78% (49)
- B11% (7)
- C8% (5)
- D3% (2)
Explanation
In Cisco SD-WAN (and SD-Access), Virtual Networks (VNs) are logically isolated segments, each mapped to a VRF. By default, traffic cannot cross VN boundaries. External fusion routers (or firewall/service nodes acting as fusion devices) are the Cisco-recommended method to enable inter-VN communication: they connect to multiple VRFs (one per VN) and selectively route or policy-filter traffic between them, often integrating with a firewall for security enforcement. GRE tunneling between fabric edges (B) is not a standard inter-VN mechanism in SD-WAN. SGTs (C) are Cisco TrustSec tags used for policy enforcement within a domain, not for routing between VNs. Route leaking on border nodes (D) is a valid technique in SD-Access for connecting Guest or shared-service VNs, but the primary and most flexible inter-VN design uses external fusion routers, making A the best answer.
Topics
Community Discussion
No community discussion yet for this question.