AWS has introduced Regional NAT Gateway, a significant improvement to how outbound internet access is handled for workloads running in private subnets. This change meaningfully reduces architectural complexity while improving availability and security.
Let’s start with the basics.
What is a NAT Gateway?
A NAT Gateway allows resources in private subnets to access the internet for outbound traffic (for example, OS updates, package downloads, external APIs) without allowing inbound internet traffic.
Traditionally, NAT Gateways were zonal resources, which came with architectural and operational overhead.
🔹 Traditional (Zonal) NAT Gateway Model
In the classic design:
One NAT Gateway per Availability Zone
NAT Gateways deployed in public subnets
AZ-specific route tables pointing to the local NAT Gateway
More AZs = more NAT Gateways + more routing complexity
Challenges:
Increased cost due to multiple NAT Gateways
Operational overhead managing routes per AZ
Public subnet dependency
Risk of misconfiguration
IP exhaustion concerns at scale
Because of these factors, many teams tried to avoid NAT Gateways where possible.
🔹 New: Regional NAT Gateway
The Regional NAT Gateway fundamentally changes this model.
Key Characteristics:
Created at the VPC level
No public subnets required
Automatically scales across all Availability Zones
A single NAT Gateway serves private subnets in all AZs
AWS manages high availability internally
This eliminates the need to think about NAT placement per AZ.
✅ Benefits
Simpler Architecture
Fewer NAT Gateways
Fewer route tables
Cleaner VPC design
Improved Security
No public subnets required
Reduced blast radius and misconfiguration risk
Built-in High Availability
No need to deploy or manage NATs per AZ
Automatically adapts as workloads scale across AZs
Lower Operational Overhead
Less maintenance
Fewer moving parts
Easier to reason about networking
📊 Architectural Impact
In AWS reference diagrams, you’ll notice that Regional NAT Gateways completely remove public subnets from the design. NAT now operates cleanly at the VPC level, which results in a more elegant and maintainable architecture.
Final Thoughts
Historically, many teams avoided NAT Gateways due to:
Cost
Maintenance complexity
IP exhaustion risks
With Regional NAT Gateway, most of these concerns are significantly reduced. You get:
Simpler architecture
Built-in high availability
Less operational burden
For modern AWS environments, this is a change well worth evaluating and adopting.
Happy Learning
Prithiviraj Rengarajan
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