Static NAT creates a permanent one-to-one mapping between a private IP and a public IP.
How it works:
- 192.168.1.10 always translates to 203.0.113.10
- The mapping is configured manually and never changes
Use cases:
- Servers needing consistent public addresses
- Devices that must be reachable from the internet
Advantages:
- Bidirectional access (internet can initiate connections)
- Consistent addressing for DNS
Disadvantages:
- Requires one public IP per device
- Doesn't conserve addresses
Static NAT is common for web servers and mail servers.