Your entire AWS infrastructure lives inside of one Amazon VPC You have an Infrastructure monitoring
application running on an Amazon instance in Availability Zone (AZ) A of the region, and another application
instance running in AZ B. The monitoring application needs to make use of ICMP ping to confirm network
reachability of the instance hosting the application.
Can you configure the security groups for these instances to only allow the ICMP ping to pass from the
monitoring instance to the application instance and nothing else” If so how?

A.
No Two instances in two different AZ’s can’t talk directly to each other via ICMP ping as that protocol is not
allowed across subnet (iebroadcast) boundaries

B.
Yes Both the monitoring instance and the application instance have to be a part of the same security group,
and that security group needs to allow inbound ICMP

C.
Yes, the security group for the monitoring instance needs to allow outbound ICMP and the application
instance’s security group needs to allow Inbound ICMP

D.
Yes, both the monitoring instance’s security group and the application instance’s security group need to
allow both inbound and outbound ICMP ping packets since ICMP is not a connection-oriented protocol