IP & Privacy Guide

Public vs Private IP Addresses

Public and private IP addresses serve different parts of a network. A public address is used for communication across the internet, while private addresses identify devices inside a local network.

Public IP addresses

An internet provider normally assigns a public address to a router, mobile gateway or business connection. Websites see an address associated with the connection’s exit point. Check yours with the Terbit IP checker.

Private IP addresses

Routers assign private addresses to laptops, phones, televisions and other local devices. Common IPv4 private ranges include 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. These addresses can be reused by many separate networks because they are not routed directly across the public internet.

How devices share a connection

Network address translation allows several private devices to use one public IPv4 address. The router tracks connections and directs returning traffic to the correct device. This address sharing is common, but it should not be mistaken for a complete security control.

Carrier-grade NAT

Some providers place multiple customers behind another translation layer. In that situation, the public address reported by a website may be shared by many subscribers, and inbound connections may require a different service arrangement.

IPv6 considerations

IPv6 can give devices globally routable addresses while still using firewall controls and temporary privacy addresses. The absence of traditional NAT does not mean a device should be exposed. Read IPv4 versus IPv6 for more detail.

Finding the right address

Use the public address when checking what websites see. Use the private address when configuring a printer or device inside your own network. Do not publish router login details or open ports unless you understand the security implications.

Reviewed 10 September 2026. Network configuration varies by provider, router and operating system.