Q82 — AWS ANS-C01 Ch.1
Question 82 of 100 | ← Chapter 1
A company has critical VPC workloads that connect to an on-premises data center through two redundant active-passive AWS Direct Connect connections. However, a recent outage on one Direct Connect connection revealed that it takes more than a minute for traffic to fail over to the secondary Direct Connect connection. The company wants to reduce the failover time from minutes to seconds. Which solution will provide the LARGEST reduction in the BGP failover time?
- A. Reduce the BGP hold-down timer that is configured on the BGP sessions on the Direct Connect connection VIFs.
- B. Configure an Amazon CloudWatch alarm for the Direct Connect connection state to invoke an AWS Lambda function to fail over the traffic.
- C. Configure Bidirectional Forwarding Detection (BFD) on the Direct Connect connections on the AWS side.
- D. Configure Bidirectional Forwarding Detection (BFD) on the Direct Connect connections on the on-premises router. ✓
Correct Answer: D. Configure Bidirectional Forwarding Detection (BFD) on the Direct Connect connections on the on-premises router.
Explanation
为了显著减少BGP(边界网关协议)的故障转移时间,从分钟级缩短到秒级,关键在于加快故障检测的速度。BFD(双向转发检测)是一种网络协议,旨在快速检测网络路径中的故障。当BFD在DirectConnect连接的本地路由器上配置时,它可以直接与AWS端的BFD会话进行交互,从而更快地检测到故障并触发故障转移。选项A减少BGP的保持定时器可能有助于,但不如BFD直接和有效。选项B使用CloudWatch和Lambda虽然可以自动化故障响应,但依赖于故障被检测到的时间。选项C仅在AWS端配置BFD不足以覆盖整个连接路径。因此,选项D在本地路由器上配置BFD提供了最大的故障转移时间减少。 查看全部