Ensure Cross-Zone Load Balancing is Enabled for Classic Load Balancers (CLBs)
elb_cross_zone_load_balancing_enabled
Checks whether cross-zone load balancing is enabled for Classic Load Balancers (CLBs). Cross-zone load balancing ensures even distribution of traffic across all registered targets in all Availability Zones, improving fault tolerance and load distribution.
Risk
If cross-zone load balancing is not enabled, traffic may not be evenly distributed across Availability Zones, leading to over-utilization of resources in certain zones and potential application performance degradation or outages.
prowler aws --checks elb_cross_zone_load_balancing_enabled
arn:partition:service:region:account-id:resource-id
Recommendation
Enable cross-zone load balancing for Classic Load Balancers to ensure even traffic distribution and enhance fault tolerance across Availability Zones.
Remediation
aws elb modify-load-balancer-attributes --load-balancer-name <load-balancer-name> --load-balancer-attributes "CrossZoneLoadBalancing={Enabled=true}"
Source Code
Resource Type
AwsElbLoadBalancer