I have the following instances, they are in the same VPC and region but different AZs, both of them are in the same SecurityGroup.
Subnets:
- us-west-2a instance-a 172.31.32.0/20
- us-west-2b instance-b 172.31.16.0/20
These two instances are not able to communicate with each other. What do I need to do to enable communication between these two AZs?