Home » Cisco » 642-661 » AS-Path prepending is used in AS1 in order to influence the return traffic from AS 4 to AS 1 through the higher speed path via AS 3. _____ needs to be configured for AS-Path prepending and a minimum of ____ of the AS number should be prepended.
Exhibit:
AS-Path prepending is used in AS1 in order to influence the return traffic from AS 4 to AS 1 through the higher speed path via AS 3. _____ needs to be configured for AS-Path prepending and a minimum of ____ of the AS number should be prepended.
A. R1; one copy
B. R2; one copy
C. R1; two copies
D. R2; two copies
E. R2; three copies
Correct Answer: D
Explanation/Reference:
Explanation: For AS 4 to prefer AS 3 path to AS 1, the path needs to be shorter than through AS 2. AS 4 to AS 1 through AS 2 path is “2 1”. AS4 through AS 3 to AS 1 is “5 3 1”. Need to prepend AS twice on R2 to make it less desirable.
