Network Address Translation (NAT)
NAT (Network Address Translation) maps one IP address space into another. This is usually done by a router to map a global IP to a local one. This allows multiple devices on a private network to share a single public IP address.
Motivation
- IPv4 Conservation: NAT conserves the limited number of IPv4 addresses
- Security: NAT hides internal IP addresses
NAT Traversal
To allow communication of devices behind NAT, different techniques exist:
- STUN/TURN
- UPnP
- NAT-PMP
- Teredo
Types of NAT
Different NAT types have their own use cases and mapping rules
- Static NAT
- Dynamic NAT
- Port Address Translation (PAT)