Solutions for Multicast Migration on AWS
Question
You have acquired a new contract from a client to move all of their existing infrastructures onto AWS.
You notice that they are running some of their applications using multicast, and they need to keep it running as such when it is migrated to AWS.
You discover that multicast is not available on AWS, as you cannot manage multiple subnets on a single interface on AWS, and a subnet can only belong to one availability zone.
Which of the following would enable you to deploy legacy applications on AWS that require multicast? Choose 2 options.
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - A and B.
Option A is CORRECT because first, we create Elastic Network Interfaces to communicate between the various subnets.
Option B is CORRECT because overlay multicast is a method of building IP level multicast across a network fabric supporting unicast IP routing, such as Amazon Virtual Private Cloud (Amazon VPC).
Option C is incorrect because it would disrupt multicast, involve additional time and cost, and not add any value.
Option D is incorrect because VPC peering and multicast are not the same.
For more information on Overlay Multicast in Amazon VPC, please visit the URL below-
https://aws.amazon.com/articles/6234671078671125Multicast is a network protocol that allows a single stream of data to be sent to multiple recipients at once, which is commonly used in some legacy applications. Unfortunately, multicast is not natively supported on AWS, as multiple subnets cannot be managed on a single interface, and a subnet can only belong to one availability zone. However, there are still some options to deploy legacy applications that require multicast on AWS, which are:
A. Provide Elastic Network Interfaces to communicate between the subnets: Elastic Network Interfaces (ENIs) are virtual network interfaces that can be attached to an instance in a VPC. By creating ENIs for each subnet that requires multicast communication and attaching them to instances in each subnet, multicast traffic can be routed between the instances via the ENIs. However, this approach can be complicated to manage, especially when there are many subnets that require multicast communication.
B. Create a virtual overlay network that runs on the OS level of the instance: A virtual overlay network can be created using a software-defined network (SDN) solution, such as VXLAN or GRE, which can run on the operating system (OS) level of the instance. By creating an overlay network that spans multiple subnets, multicast traffic can be routed between the instances that are connected to the overlay network. This approach provides more flexibility and easier management, but it may require additional configuration and setup time.
C. Create all the subnets in a single VPC: By creating all the subnets in a single VPC, they can communicate with each other directly without the need for multicast. This approach simplifies the network architecture and management, but it may not be feasible in some scenarios, such as when there are geographic or regulatory requirements to use multiple VPCs.
D. Create all the subnets on a different VPC and use VPC peering between them: By creating each subnet in a separate VPC and establishing VPC peering connections between them, multicast traffic can be routed between the instances in different VPCs. This approach provides more isolation and security between the subnets, but it may require additional setup time and configuration, and it may incur additional network costs.
In summary, options A and B are the two options that can enable the deployment of legacy applications that require multicast on AWS. Option A uses ENIs to enable multicast communication between subnets, while option B uses a virtual overlay network that runs on the OS level of the instance. Option C and D are alternative approaches that may not require multicast but may be feasible in some scenarios.
