Cloud providers implement NAT for private subnet internet access:
AWS NAT Gateway:
- Managed NAT for VPC private subnets
- Highly available within an AZ
- Charges for data processing and hourly usage
Azure NAT Gateway:
- Similar managed service
- Supports multiple public IPs
GCP Cloud NAT:
- Outbound NAT for private instances
- Automatic port allocation and scaling
Common pattern:
- Private subnets for application servers
- NAT gateway for outbound internet access
- Load balancer for inbound traffic
- No public IPs on individual instances
Cloud NAT is managed PAT with high availability.