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 monitoringinstance to the application instance and nothing else” If so how?
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
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
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
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 connectionoriented protocol