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Answer: Remove all the VPC CIDR prefixes from the list of subnets advertised through the local Direct Connect connection. Add the company's entire AWS environment aggregate route to the list of subnets advertised through the local Direct Connect connection., Remove all the VPC CIDR prefixes from the list of subnets advertised through the local Direct Connect connection. Add both Regional aggregate IP prefixes to the list of subnets advertised through the Direct Connect connection on both sides of the network. Configure data center routers to make routing decisions based on the BGP communities received.
The question revolves around optimizing the routing setup for a multi-site hybrid infrastructure to ensure efficient cross-Region data transfers without modifying the original traffic routing goal under normal network operations. The key is to ensure that traffic can still follow the shortest geographical path from source to destination, while also providing a fallback in case of issues with the private WAN connection. Options A and E propose modifications that align with these requirements. Option A suggests removing all VPC CIDR prefixes and adding the company's entire AWS environment aggregate route to the list of subnets advertised through the local Direct Connect connection. This approach simplifies routing by aggregating routes, which can help in reducing the size of the routing table and potentially improving routing efficiency. However, it might not directly address the issue of cross-Region data transfers in case of WAN connection issues. Option E, on the other hand, suggests removing all VPC CIDR prefixes and adding both Regional aggregate IP prefixes to the list of subnets advertised through the Direct Connect connection on both sides of the network, along with configuring data center routers to make routing decisions based on the BGP communities received. This approach not only simplifies routing by aggregating routes but also introduces a mechanism (BGP communities) to influence routing decisions dynamically, which can be crucial in rerouting traffic efficiently in case of WAN connection issues. Therefore, options A and E are the most suitable modifications to meet the requirements.
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A company operates a multi-site hybrid infrastructure with resources deployed in AWS us-east-1 and eu-west-2 Regions, as well as in on-premises data centers in the US and UK. The company uses transit gateways in both AWS Regions to connect 15 non-overlapping VPCs, with a transit gateway peering connection established between the two Regions. The on-premises data centers are interconnected via a private WAN, with dynamic IP routing using iBGP. Each data center connects to AWS through a Direct Connect connection terminated on a Direct Connect gateway, associated with a local transit gateway via a transit VIF. Traffic is routed based on the shortest geographical path, with cross-Region traffic using the private WAN to minimize AWS costs. The transit gateway associations on the Direct Connect gateway advertise only local Region VPC CIDR prefixes, while routes to the other Region are learned via BGP from the other data center in non-aggregated form. Due to recent private WAN issues disrupting cross-Region traffic, the network engineer must modify the routing setup to prevent future interruptions without altering normal traffic routing goals.
Which modifications will meet these requirements? (Choose two.)
A
Remove all the VPC CIDR prefixes from the list of subnets advertised through the local Direct Connect connection. Add the company's entire AWS environment aggregate route to the list of subnets advertised through the local Direct Connect connection.
B
Add the CIDR prefixes from the other Region VPCs and the local VPC CIDR blocks to the list of subnets advertised through the local Direct Connect connection. Configure data center routers to make routing decisions based on the BGP communities received.
C
Add the aggregate IP prefix for the other Region and the local VPC CIDR blocks to the list of subnets advertised through the local Direct Connect connection.
D
Add the aggregate IP prefix for the company's entire AWS environment and the local VPC CIDR blocks to the list of subnets advertised through the local Direct Connect connection.
E
Remove all the VPC CIDR prefixes from the list of subnets advertised through the local Direct Connect connection. Add both Regional aggregate IP prefixes to the list of subnets advertised through the Direct Connect connection on both sides of the network. Configure data center routers to make routing decisions based on the BGP communities received.