Hybrid Network Routing and Connectivity – ANS-C01 Study Guide

THE AWS CERTIFIED ADVANCED NETWORKING – SPECIALTY EXAM OBJECTIVES COVERED IN THIS CHAPTER MAY INCLUDE, BUT ARE NOT LIMITED TO, THE FOLLOWING:

• Domain 3: Network Management and Operations 

Task Statement 3.1: Maintain routing and connectivity on AWS and hybrid networks.

Industry-Standard Routing Protocols Used in AWS Hybrid Networks

When creating a hybrid network with AWS, a standards-based routing protocol is required for interoperability between customer networks and AWS. You must use a routing protocol that is designed specifically to interconnect different accounts, or autonomous systems, together. The industry-standard routing protocol that is used in AWS hybrid networks is the Border Gateway Protocol (BGP), the protocol used to exchange network reachability information between your on-premises network and the Amazon cloud, which is typically to a VPC. BGP can be used for an organization’s internal routing in which case it’s referred to as the internal Border Gateway Protocol (iBGP). When two different entities, which are referred to as autonomous systems, interconnect their networks, the routing protocol used is external Border Gateway Protocol (eBGP). AWS has documented vendor configuration examples at https://docs.aws.amazon.com/vpn/latest/s2svpn/cgw-dynamic-routing-examples.html that have been tested and validated for the interconnections.

Amazon also supports the use of static routing, where routes are manually configured, and no dynamic routing protocol is required at the interconnection point. A static route is manually configured in the interconnected routers and is not learned through a dynamic routing protocol. Static routes are typically used when there is a need for a specific path to be taken for a specific destination, regardless of any other routing information that may be available.

Optimizing Routing

In this section, you will learn about ways to optimize routing inside of, and into, the AWS cloud. Optimization can improve performance, increase availability, improve security, and lower the cost of your network and AWS deployment. A number of tools, techniques, and best practices can help with optimization.

• Optimization is achieved by adjusting configuration parameters in various services such as the AWS Route 53 DNS service by taking advantage of its advanced routing policies to route traffic to the most optimal endpoints in your network.
• Content delivery networks such as CloudFront push content to worldwide edge locations for better response times to a globally dispersed client base.
• The AWS Global Accelerator utilizes the AWS high-bandwidth global network instead of traffic having to traverse the Internet to get to AWS services.
• Using Direct Connect bypasses the public Internet and uses a private connection to provide a reliable and secure connection.
• PrivateLink is used for private access to AWS services and VPC endpoint services over a private IP address and for all traffic to remain inside of the AWS network.
• AWS elastic IP addresses improve availability and allow you to assign a static IP address to your resources to improve availability.
• VPC peering and VPC endpoints can be implemented for inter-VPC communications inside of AWS to privately access services in an Amazon VPC without requiring a NAT gateway, VPN, or Direct Connect connection.
• The Transit Gateway is used to connect multiple VPCs, on-premises networks, and remote networks to a single gateway, which allows you to reduce costs and simplify the management of the network.

When you implement these best practices, routing is optimized to improve the performance, scalability, and security of your network infrastructure.