You are designing an overlay solution for two Data Centers based on the Aruba CX platform. Each Data Center has two rooms and each room is its own fabric. What is used for EVPN advertisements…

Question

Options

• ANot supported design
• BiBGP
• CStatic Routing
• DeBGP

• A
  9% (4)
• B
  15% (7)
• C
  4% (2)
• D
  72% (34)

Explanation

In Aruba CX EVPN designs, each fabric (room) operates with its own BGP Autonomous System (AS) number. When two separate fabrics need to exchange EVPN routes, they are by definition in different AS domains, making eBGP the required protocol for inter-fabric EVPN advertisements - it is purpose-built for BGP peering across AS boundaries.

Why the distractors are wrong:

• A (Not supported): This design is fully supported on Aruba CX; inter-DC/inter-room overlay is a documented use case.
• B (iBGP): iBGP peers within the same AS - it handles route distribution inside a single fabric, not between separate fabrics with distinct AS numbers.
• C (Static Routing): Static routes have no mechanism to carry EVPN NLRI (Network Layer Reachability Information); EVPN is inherently a BGP address family extension.

Memory tip: Think of each room/fabric as its own "country" with its own AS passport. Crossing the border between countries requires external BGP - eBGP. iBGP only works for travel within the same country.

No community discussion yet for this question.