A manufacturing firm is dual-homed to one ISP with two links and must make all internal routers prefer the primary exit for outbound traffic, while asking the ISP to prefer the primary ingress path without changing the local AS path length. Which BGP path-preference attribute design achieves that outbound and inbound influence?
Select an answer to reveal the explanation.
Short Explanation
You're steering traffic like outbound signs you control and inbound suggestions your neighbor hears. Local preference plus MED gives you that directional-control without touching your AS path.
Full Explanation
The correct design respects attribute scope and direction, because local preference is carried in iBGP to influence outbound exit selection for all internal routers, while MED is sent to the neighboring AS to suggest preferred inbound entry without altering AS-path length. Relying on weight fails by concept because weight is locally significant only to a single router and is not advertised to iBGP peers. Prepending for outbound and setting local preference on the ISP fails by concept because AS-path length affects inbound best-path decisions by others, not local outbound, and local preference is not exported to eBGP. Setting low local preference on the primary fails by concept because lower local preference deprioritizes that path, reversing the intended outbound outcome. Exam caveat: map weight and local preference to outbound and MED and prepending to inbound influence. Practical check: confirm propagation with BGP table outputs on both internal peers and the provider side.