I have set up an Amazon Virtual Private Cloud (VPC). Inside the VPC I have 2 networks in which I create instances. For security reasons I want to put some network access control lists (Network ACL) on those networks, besides the machines firewall. Following the Amazon example I have a public network (exposed to internet access) 10.0.0.0/24 and 3 private network 10.0.1.0/24, 10.0.2.0/24, 10.0.3.0/24. The traffic between them is routed.
So for the network 10.0.1.0/24 as ACL's I put this:
Inbound:
10.0.0.0/24 port 80 (HTTP)
10.0.0.0/24 port 22 (SSH)
10.0.2.0/24 port 3306 (MySql)
10.0.3.0/24 port 3306 (MySql)
Outbound
ALL ALL
For the networks 10.0.2.0/24 and 10.0.3.0/24:
Inbound
10.0.1.0/24 port 3306 (MySql)
Outbound
ALL ALL
For the public network 10.0.0.0/24 in here I have an exposed load balancer, which is redirecting traffic to the private network 10.0.1.0/24, where an app is responding over HTTP:
Inbound
0.0.0.0/0 port 80 (HTTP)
0.0.0.0/0 port 443 (HTTPS)
0.0.0.0/0 port 22 (SSH)
Outbound
ALL ALL
The problem is, when I put those rules in action, all traffic freezes and the app is not available. What's happening? Am I doing something wrong?