Exam AWS Certified Advanced Networking - Specialty ANS-C01 topic 1 question 111 discussion

A&B Both ipv4 and ipv6 BGP sessions can be established with one private VIF After creating an ipv4 BGP peering on the VIF at the beginning, you can add an ipv6 peering with "add peering" And you have to enable BFD

https://aws.amazon.com/blogs/networking-and-content-delivery/dual-stack-ipv6-architectures-for-aws-and-hybrid-networks/#:~:text=AWS%20Direct%20Connect,prefixes%20or%20larger. Looks like A and B

B) This option provides separate VIFs for IPv4 and IPv6, allowing for distinct routing and peering sessions. BFD helps detect connectivity issues more quickly, improving reliability. D) Similar to Option B, this option provides separate VIFs for IPv4 and IPv6. It advertises all routes on all peering sessions, ensuring redundancy. Bidirectional Forwarding Detection (BFD) is optional in this case. Option A: Mixing IPv4 and IPv6 on the same peering session may not provide the desired separation of traffic. Option C: Advertising IPv6 routes on an IPv4 peering session is not a recommended practice. Option E: Reducing the BGP hello timer to 5 seconds may increase the BGP control plane traffic and could lead to unnecessary overhead. The BFD solution in Options B and D is more specific to failure detection.

I also think is BD, they are asking for solutions that could work, B & D would meet the requirements. They are not asking for steps for one solution, A is not HA

The solutions must be HA, the question is asking for two solutions that would work, not necessarily a combination of steps, I think.

IP4 and IP6 BGP peerings can be created using one VIF, however advertise IP4 addresses on IP4 peering and IP6 on IP6 peering .

Bは確実。 Dも正解だと思うが、BFDを有効化しないのは引っかかる。

Should it be B & D?