Elb cross zone enabled remediation

Using Console

Using CLI

To remediate the misconfiguration “ELBs should have cross-zone enabled” in AWS using AWS CLI, follow these steps:

Open the AWS CLI on your local machine.
Run the following command to enable cross-zone load balancing for all existing ELBs in the current region:

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

Replace <ELB_NAME> with the name of the ELB that needs to be remediated.

Run the following command to enable cross-zone load balancing for all new ELBs created in the current region:

aws elb create-lb-cookie-stickiness-policy --load-balancer-name <ELB_NAME> --policy-name "cross-zone-policy" --cookie-expiration-period 60

Replace <ELB_NAME> with the name of the ELB that needs to be remediated.

Verify that cross-zone load balancing is enabled for the ELB by running the following command:

aws elb describe-load-balancer-attributes --load-balancer-name <ELB_NAME> --query 'LoadBalancerAttributes.CrossZoneLoadBalancing.Enabled'

Replace <ELB_NAME> with the name of the ELB that was remediated.

Repeat these steps for all ELBs in the current region that require remediation.

Using Python

To remediate the misconfiguration of ELBs not having cross-zone enabled in AWS using Python, you can follow the below steps:

Import the necessary libraries:

import boto3

Create an AWS client for Elastic Load Balancing:

elb_client = boto3.client('elbv2')

Get the list of all the ELBs:

elbs = elb_client.describe_load_balancers()

Loop through each ELB and check if cross-zone load balancing is enabled. If not, enable it:

for elb in elbs['LoadBalancers']:
    elb_arn = elb['LoadBalancerArn']
    elb_attributes = elb_client.describe_load_balancer_attributes(LoadBalancerArn=elb_arn)
    if not elb_attributes['Attributes'][0]['Value']:
        elb_client.modify_load_balancer_attributes(
            LoadBalancerArn=elb_arn,
            Attributes=[
                {
                    'Key': 'load_balancing.cross_zone.enabled',
                    'Value': 'true'
                }
            ]
        )

Verify that cross-zone load balancing is enabled for all the ELBs:

for elb in elbs['LoadBalancers']:
    elb_arn = elb['LoadBalancerArn']
    elb_attributes = elb_client.describe_load_balancer_attributes(LoadBalancerArn=elb_arn)
    if not elb_attributes['Attributes'][0]['Value']:
        print(f"{elb['LoadBalancerName']} - Cross-Zone Load Balancing is not Enabled")
    else:
        print(f"{elb['LoadBalancerName']} - Cross-Zone Load Balancing is Enabled")

By following these steps, you can remediate the misconfiguration of ELBs not having cross-zone enabled in AWS using Python.

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Elb cross zone enabled remediation

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