Ensure a log metric filter and alarm exist for changes to network gateways

Property
Language
Severity
Service	cloudwatch
Provider	AWS

Description#

You can do real-time monitoring of API calls by directing CloudTrail logs to CloudWatch Logs and establishing corresponding metric filters and alarms.
Network gateways are required to send and receive traffic to a destination outside a VPC.

CIS recommends that you create a metric filter and alarm for changes to network gateways. Monitoring these changes helps ensure that all ingress and egress traffic traverses the VPC border via a controlled path.

Resolution#

Create an alarm to alert on network gateway changes