In a Cisco SD-Access fabric, which node facilitates connectivity between the fabric and networks external to the fabric?

Refer to the exhibit. A network engineer is designing an OSPF solution to connect a company's remote to a newly provisioned MPLS VPN backbone. Some of the branches have a direct dark fiber connection between each other. The engineer wants to ensure that the dark fibers are used only when the MPLS core is unavailable. Which solution must the engineer choose?

Refer to the exhibit. An engineer is designing a hierarchical ISIS solution for an enterprise customer with these requirements:
- Users in areas 25 and 55 send and receive traffic from both backbone
areas.
- Link flaps in areas 35 and 45 must not impact other areas.
- Routers will double within the next 12 months in areas 35 and 45.
Which design must the engineer select?

A network solution is being designed for a company that connects to multiple Internet service providers. Which Cisco proprietary BGP path attribute will influence outbound traffic flow?

What is the purpose of a border node in a Cisco SD-Access fabric?