Refer to the exhibit. A network engineer from ISP 2 is designing the BGP architecture with a requirement of preventing their customer AS 65001 from becoming a transit AS, using the following configuration.
Router BGP 65000
Neighbor 10.0.0.1 remote-as 65001
Neighbor 10.0.0.1 route-map BGP-ROUTE-policy in
Which Cisco IOS command should be used within the route-map to achieve the goal on ISP 2 from AS 65000?
A. route-map BGP-ROUTE-POLICY permit 10 set community no-advertise additive
B. ip as-path access-lists 1 permit^65001$
!
route-map BGP-ROUTE-POLICY deny 10
match as-path 1
!
route-map BGP-ROUTE-POLICY permit 10
C. ip as-path access-list 1 permit^65001$
!
route-map BGP-ROUTE-POLICY permit 10 match as-path 1
D. route-map BGP-ROUTE-POLICY permit 10 set community no-export additive
Once AS 65000 receives prefixes from 65001, in order to avoid that 65001 will become a transit AS, 65000 should not export those prefixes beyond (no-export community).
I would say the correct ansswer is D