You are an employee of ISP A. You must not allow traffic between ISP B and ISP C to cross your
network, but customers of ISP B and ISP C must be able to reach your customers. Referring to the
exhibit, which two actions would do this? (Choose two.)
A.
Use communities to identify and filter routes.
B.
Use policy to filter routes on AS number.
C.
Use origin code to identify and filter routes.
D.
Use the well-known no-advertise community.
Explanation:
should A and B
I agree with dontbycisco… Answer D is contradictory with demand that customers from ISP B and ISP C must be able to reach customers from ISP A.
I agree, A and B are right.
To avoid a transit traffic we should configure no-export instead of no-advertise
yes, A and B , Nakano is right – only no-export helps ISP A not to be a transit.
this same question repeats many times and answer is A & B
no-advertised never be the answer