Refer to the exhibit.

The No-Export community is the appropriate filtering mechanism when a design must prevent an autonomous system from becoming an unintended transit path. In a multihomed BGP design, a customer AS can accidentally advertise routes learned from one provider to another provider. If that happens, external traffic may cross the customer network to reach destinations beyond it, making the customer a transit AS. Applying No-Export to the appropriate learned or advertised routes instructs the receiving AS not to advertise those routes outside its own AS boundary. This helps contain route propagation and prevents third parties from learning paths through AS64512. Maximum-prefix protects a router from receiving too many routes; it is not a transit-prevention policy. No-advertise is more restrictive and prevents advertisement to all peers, which may break required internal or provider reachability. Next-hop is a path attribute used for reachability and path selection, not a route-leak prevention mechanism. In production, No-Export should be combined with explicit prefix filters so policy does not depend on community handling alone. Reference topics: BGP No-Export, transit AS prevention, route-leak control, BGP communities, multihoming.