Refer to the exhibit. An engineer is designing the traffic flow for AS 111. Traffic from AS 111 should be preferred via AS 100 for all external routes. A method must be used that only affects AS…

BGP communities are informational tags that typically require the neighboring AS to have a policy configured to act on them, meaning they cannot unilaterally control outbound path selection within AS 111 alone.

MED is a BGP attribute sent to external neighbors to influence which path they use when sending traffic into the local AS, making it an inbound traffic control mechanism rather than an outbound one.

Local preference is an iBGP attribute that is shared among all routers within AS 111 to indicate the preferred exit point for traffic leaving the AS. By setting a higher local preference on routes learned from AS 100, all routers in AS 111 will prefer those paths for outbound forwarding. Because local preference is never advertised outside the local AS, this change affects only AS 111 with no impact on neighboring autonomous systems.

AS path prepending makes a path appear longer to external neighbors to discourage inbound traffic, not a mechanism for controlling outbound routing decisions within the local AS.