IP & Privacy Guide
Public vs Private IP Addresses
A public IP address represents a connection on the wider internet. A private IP address works only inside a local network. Confusing the two causes many problems with remote access, troubleshooting and privacy expectations.
Public addresses
A public address is globally routable and normally assigned by an internet provider, mobile carrier, hosting company or cloud platform. Websites see the public address from which a request reaches them. For a household, that is usually the router's internet-facing address rather than the internal address of each device.
A public address may be dynamic or static. It may also be shared through carrier-grade NAT, especially on mobile and some broadband services. In that case, the address visible online is not dedicated to one customer.
Private addresses
Private ranges are reserved for use within local networks. Common IPv4 examples begin with 10., 172.16 through 172.31, or 192.168.. A router can reuse these ranges because private addresses are not routed directly across the public internet.
Your laptop might be 192.168.1.20 at home and receive a completely different private address at work. Neither address tells an outside website where to send traffic without the router's translation and connection state.
What NAT does
Network address translation maps traffic from private devices to a public address. The router tracks connections so responses return to the correct device. NAT conserves IPv4 space, but it is not a complete firewall strategy. Security still depends on firewall rules, router configuration, software updates and the services exposed.
Why this matters in practice
Remote access
If you want to reach a home device from outside, knowing its private address is not enough. You may need a public address, firewall permission and a secure remote-access method. If the provider uses carrier-grade NAT, ordinary port forwarding may not work.
Troubleshooting
If devices can communicate locally but cannot reach the internet, check the private network, gateway, DNS and public connection separately. The distinction narrows down where the failure occurs.
Privacy
Websites usually see the public address, not the private one. Browser technologies can sometimes expose local or interface information, which is why a WebRTC test is useful when checking a VPN.
How to find each address
Use the Terbit homepage to see the public IP visible to websites. To find a private address, open the network details on the device or router. Do not publish router screenshots that contain Wi-Fi names, hardware identifiers, administrative addresses or other unnecessary information.
Terbit's practical point of view
Use the public address when diagnosing how the internet sees the connection. Use the private address when diagnosing communication inside the local network. Never treat NAT alone as protection, and avoid opening ports merely to make a service convenient. Prefer authenticated, encrypted remote-access solutions with limited exposure.
Frequently asked questions
Can private addresses be duplicated?
Yes, across separate networks. Two homes can both use 192.168.1.1 without conflict because the addresses are local.
Why does my router show a different WAN address?
The provider may be using carrier-grade NAT, or you may have more than one router performing translation.
Does a VPN change my private address?
Usually not. It changes the route and public exit address; the local Wi-Fi address often remains the same.
Reviewed and expanded 1 October 2026. Educational information only. Network and location results are approximate and do not guarantee identity, security or anonymity.