1. Configuration – ELB in front of NAT instance.
2. NAT instance in it’s own security group (NAT_SG); ELB in it’s own Security Group (ELB_SG)
3. Inbound Rules – HTTP/S with a source of ELB_SG
4. Outbound Rules – HTTP/S with a Destination of 0.0.0.0/0 (all)

Multi AZ Deployments  -and NATS

• Each AZ needs it’s own NAT instance. This allows the NAT to retain the session for returning traffic – and route it back to the same instance that sent the traffic out.
• NAT instances go straight to the IgW – not through the ALB / ELB or any firewall.

For cloud migration projects or cloud consulting on AWS, GCP or Azure, contact Cloud Migration Architect

The post NAT Route Tables–Multi AZ Deployments– AWS appeared first on Anuj Varma, Hands-On Technology Architect, Clean Air Activist.