ELBv1 load balancer cross zone load balancing should be enabled

Description

Having Availability Zone with the Cross-Zone Load Balancing feature enabled for the VPC reduces the risk of failure at a single location as the AWS Elastic Load Balancers distribute the traffic to the other locations.

Remediation Steps

AWS Console

  • Navigate to EC2.

  • On the navigation pane, under LOAD BALANCING, choose Load Balancers.

  • Select the load balancer associated with your VPC.

  • On the Description tab, choose Change cross-zone load balancing setting.

  • On the Configure Cross-Zone Load Balancing page, select Enable.

  • Choose Save.

AWS CLI

  • aws elb modify-load-balancer-attributes --load-balancer-name <name> --load-balancer-attributes "{\"CrossZoneLoadBalancing\":{\"Enabled\":true}}"

Terraform

  • Ensure that the aws_elb cross_zone_load_balancing field is set to “true”.

Example Configuration

resource "aws_elb" "example" {
  cross_zone_load_balancing = true
  # other required fields here
}