An organization is hosting a scalable web application using AWS. The organization has
configured ELB and Auto Scaling to make the application scalable.
Which of the below mentioned statements is not required to be followed for ELB when the
application is planning to host a web application on VPC?
A.
The ELB and all the instances should be in the same subnet.
B.
Configure the security group rules and network ACLs to allow traffic to be routed between the
subnets in the VPC.
C.
The internet facing ELB should have a route table associated with the internet gateway.
D.
The internet facing ELB should be only in a public subnet.
Explanation:
Amazon Virtual Private Cloud (Amazon VPC) allows the user to define a virtual networking
environment in a private, isolated section of the Amazon Web Services (AWS) cloud. The user
has complete control over the virtual networking environment. Within this virtual private cloud, the
user can launch AWS resources, such as an ELB, and EC2 instances. There are two ELBs
available with VPC: internet facing and internal (private) ELB. For the internet facing ELB it is
required that the ELB should be in a public subnet. After the user creates the public subnet, he
should ensure to associate the route table of the public subnet with the internet gateway to
enable the load balancer in the subnet to connect with the internet. The ELB and instances can
be in a separate subnet. However, to allow communication between the instance and the ELB the
user must configure the security group rules and network ACLs to allow traffic to be routed
between the subnets in his VPC.
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/CreateVPCForELB.ht
ml