gen-define-nat-network-address-translation-and-give-one-short-wo-8406

Define NAT (network address translation) and give one short worked example.

# Network Address Translation (NAT) **NAT** is a technique that modifies IP address information in packet headers as traffic passes through a router or firewall. It allows multiple devices on a private network to share a single public IP address when accessing the internet. ## Worked Example **Scenario:** Home network with router using NAT - **Router's public IP:** 203.0.113.5 - **Private device IP:** 192.168.1.10 **Outbound traffic:** 1. Your computer (192.168.1.10:45678) sends a request to a web server (93.184.216.34:80) 2. NAT router replaces the source address: - **Before NAT:** `192.168.1.10:45678 → 93.184.216.34:80` - **After NAT:** `203.0.113.5:54321 → 93.184.216.34:80` 3. Router records this translation in its NAT table **Inbound response:** 1. Web server replies to `203.0.113.5:54321` 2. Router checks NAT table and translates back: - **Before NAT:** `93.184.216.34:80 → 203.0.113.5:54321` - **After NAT:** `93.184.216.34:80 → 192.168.1.10:45678` 3. Your computer receives the response The web server never sees your private IP—only the router's public IP.