Scheduled Service Change - Enable Security Group References Across Transit Gateway in AWS

<div>AWS recently released the option of allowing Security Group referencing on Transit Gateways. This allows you to create inbound security rules that reference security groups defined in other AWS VPCs attached to a Transit Gateway within the same region. These cross-gateway references allow finer control of incoming traffic compared the CIDR-block scoping. See <a href="https://aws.amazon.com/blogs/networking-and-content-delivery/introducing... ">this announcement from AWS</a> for more information. <br><br>This is an expansion of functionality, and no existing network functionality will be changed. For details about Direct Connect and Transit Gateway configuration in Cornell AWS accounts<a href="https://confluence.cornell.edu/display/CLOUD/Cornell+AWS+Direct+Connect"> refer to this Confluence page</a>.</div>