Faster Failure Detection Times

Answer - B.

The AWS documentation mentions the following on BFD.

Bidirectional Forwarding Detection (BFD) is a network fault detection protocol that provides fast failure detection times, which facilitates faster re-convergence time for dynamic routing protocols.

It is independent of media, routing protocol, and data.

We recommend enabling BFD when configuring multiple AWS Direct Connect connections or when configuring a single AWS Direct Connect connection and a VPN connection as a back up to ensure fast detection and failover.

You can configure BFD to detect link or path failures and update dynamic routing as Direct Connect quickly terminates BGP peering so that backup routes can kick in.

This ensures that the Bidirectional Forwarding Detection (BGP) neighbor relationship is quickly torn down instead of waiting for 3 keep-alives to fail at a hold-down time of 90sec.

For more information on Bidirectional Forwarding Detection, please visit the below URL:

https://aws.amazon.com/premiumsupport/knowledge-center/enable-bfd-direct-connect/

The correct answer is B. BFD (Bidirectional Forwarding Detection).

AWS Direct Connect is a service that provides dedicated network connections from on-premises data centers to AWS services. It can be used to establish a private, high-speed, and low-latency connection to AWS services, bypassing the public internet.

BFD is a protocol that provides rapid failure detection times for network devices, such as routers. It works by periodically sending small packets, called BFD control packets, between the devices. If a device stops receiving these packets, it assumes that the other device is no longer reachable and takes appropriate action, such as rerouting traffic to an alternative path.

By enabling BFD on the Direct Connect link, customers can achieve faster failure detection times compared to relying on the default network failure detection mechanisms. This can help to minimize the impact of network failures on the applications running on the AWS services.

Peering refers to the connection between two networks for the purpose of exchanging traffic. BGP (Border Gateway Protocol) is a routing protocol used to exchange routing information between different networks. VPN (Virtual Private Network) is a technology used to create a secure connection between two endpoints over a public network, such as the internet. While these features are relevant to AWS Direct Connect, they do not directly relate to providing faster failure detection times.