My customer is implementing the Container Gateway 9.3 in an AWS infrastructure. My question is about the link of documentation -
https://docops.ca.com/ca-api-gateway/9-3/en/install-configure-upgrade/configure-the-software-gateway/prepare-the-network-software 

In Cluster consideration, the "replay protection synchronization between nodes is accomplished by multicast UDP port 8777" but my customer told us that the multicast isn´t compatible with AWS. 

1. What problem will we have in not using Multicast on port UDP 8777 and use only TCP 8777? 
2. How are other customers dealing with this problem? 

Release: MSPAPE99000-9.3-API Gateway Essentials-MSP
Component:

Regarding AWS – yes, AWS VPC does not support multicast or broadcast and multicast is possible only by using some 3rd party images, e.g. 
Source: https://aws.amazon.com/marketplace/pp/B071RMCZ1X

The reason this does not work is due to the Hazelcast feature. Hazelcast will work in our standard gateway image but does not work in the container based gateway.