Dynamic NAT assigns public IPs from a pool on first-come, first-served basis.
How it works:
- You configure a pool of public addresses
- When a device needs internet access, NAT assigns an available public IP
- Mapping lasts until connection ends or times out
- Public IP returns to pool for reuse
Example:
- Pool has public IPs
- First devices get unique public addresses
- Device must wait until one becomes available
Disadvantages:
- Still needs one public IP per active connection
- Connections fail if pool exhausted
Dynamic NAT is rarely used today. PAT is far more common.