A user has created an ELB with three instances. How many security groups will ELB create by
default?
A.
3
B.
5
C.
2
D.
1
Explanation:
Elastic Load Balancing provides a special Amazon EC2 source security group that the user can
use to ensure that back-end EC2 instances receive traffic only from Elastic Load Balancing. This
feature needs two security groups: the source security group and a security group that defines the
ingress rules for the back-end instances. To ensure that traffic only flows between the load
balancer and the back-end instances, the user can add or modify a rule to the back-end security
group which can limit the ingress traffic. Thus, it can come only from the source security group
provided by Elastic load Balancing.