Network Address Translation (NAT): How It Really Works

NAT allows devices on private networks to access the internet using a single public IP address. It's a crucial mechanism for dealing with IPv4 address shortages and maintaining basic network security.

How NAT Works

• Source NAT (SNAT): Translates internal IPs to a public IP for outbound traffic
• Destination NAT (DNAT): Maps public-facing ports to internal hosts
• Port Address Translation (PAT): Multiple devices share one IP using port numbers

Downsides

NAT introduces complexities like broken peer-to-peer connections, dependency on port forwarding, and difficulty with real-time protocols. IPv6 aims to eliminate the need for NAT entirely.