**To change the default action**

This example changes the default action for the specified listener.

Command::

  aws elbv2 modify-listener --listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2 --default-actions Type=forward,TargetGroupArn=arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-new-targets/2453ed029918f21f

Output::

  {
    "Listeners": [
        {
            "Protocol": "HTTP",
            "DefaultActions": [
                {
                    "TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-new-targets/2453ed029918f21f",
                    "Type": "forward"
                }
            ],
            "LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
            "Port": 80,
            "ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/f2f7dc8efc522ab2"
        }
    ]
  }

**To change the server certificate**

This example changes the server certificate for the specified HTTPS listener.

Command::

  aws elbv2 modify-listener --listener-arn arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/0467ef3c8400ae65 --certificates CertificateArn=arn:aws:iam::123456789012:server-certificate/my-new-server-cert

Output::

  {
    "Listeners": [
        {
            "Protocol": "HTTPS",
            "DefaultActions": [
                {
                    "TargetGroupArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:targetgroup/my-targets/73e2d6bc24d8a067",
                    "Type": "forward"
                }
            ],
            "SslPolicy": "ELBSecurityPolicy-2015-05",
            "Certificates": [
                {
                    "CertificateArn": "arn:aws:iam::123456789012:server-certificate/my-new-server-cert"
                }
            ],
            "LoadBalancerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:loadbalancer/app/my-load-balancer/50dc6c495c0c9188",
            "Port": 443,
            "ListenerArn": "arn:aws:elasticloadbalancing:us-west-2:123456789012:listener/app/my-load-balancer/50dc6c495c0c9188/0467ef3c8400ae65"
        }
    ]
  }