AWS Certified Advanced Networking – Specialty ANS-C00 – Question172

You have 4 Direct Connect connections from your datacenter. Site A advertises 172.16.0.0/16 AS 65000, Site B advertises 172.16.0.128/25 AS 65000 65000 65000, Site C advertises 172.0.0.0/8 AS 65000 and Site D advertises 172.16.0.0/24 AS 65000. Which site will AWS choose to reach your network?

A.
Site A: 172.16.0.0/16 AS 65000
B. Site B: 172.16.0.128/25 AS 65000 65000 65000
C. Site C: 172.0.0.0/8 AS 65000
D. Site D: 172.16.0.0/24 AS 65000

Correct Answer: B

Explanation:

Explanation: 172.16.0.128/25 AS 65000 65000 65000. The most specific prefix is always the first choice for BGP routing. Also, AWS will not accept an advertisement of a network less than /16.