Select AWS VPC. (Optional) Add a label to identify the location or function of the source. Clear the Enabled option to disable communication between the host and the firewall. The syntax is: ec2.<your_AWS_region>.amazonaws.com; for AWS China it is: ec2.<AWS_region>.amazonaws.com.cn (Optional) Enable timeout when the source is disconnected. When the specified limit is reached, if the source is inaccessible, or if the source does not respond, the firewall will close the connection to the source.