Elastic Load Balancing
Classic Load Balancers

Troubleshoot a Classic Load Balancer: Client Connectivity

If your Internet-facing load balancer in a VPC is not responding to requests, check for the following:

Your Internet-facing load balancer is attached to a private subnet

Verify that you specified public subnets for your load balancer. A public subnet has a route to the Internet Gateway for your virtual private cloud (VPC).

A security group or network ACL does not allow traffic

The security group for the load balancer and any network ACLs for the load balancer subnets must allow inbound traffic from the clients and outbound traffic to the clients on the listener ports. For more information, see Security Groups for Load Balancers in a VPC.