How Do IP Addresses Work? (2026)

Every device on the internet — your phone, this website’s server, the router at your coffee shop — has an IP address, and the entire internet is built on one simple contract: label every packet of data with where it’s from and where it’s going, and the network will find a way to deliver it. This guide explains how that actually happens, in plain English.

What an IP address is

An IP (Internet Protocol) address is a numeric label that identifies a device on a network. IPv4 addresses look like 203.0.113.7; IPv6 addresses look like 2001:db8::1a2f. Two facts matter more than the format: addresses are structured (the beginning identifies a network, the end identifies a device on it), and they’re globally coordinated, so no two devices on the public internet claim the same one at the same time.

Think postal system: the country/city part of a mailing address gets a letter to the right sorting facility; the street and house number finish the job. IP addresses work the same way — network first, device last.

How packets actually find your device

When you load a website, your data doesn’t travel as one stream — it’s chopped into packets, and each packet carries a header listing its source IP and destination IP. Delivery happens hop by hop:

1. Your device hands the packet to your router — the only gateway it knows.
2. Your router forwards it to your ISP, which checks the destination IP against its routing table — a live map of which neighboring networks lead toward which address blocks.
3. Each router along the path repeats that lookup, moving the packet one network closer. Ten to twenty hops is typical for a cross-internet trip.
4. The destination network delivers the packet to the exact device, and replies make the same journey back to your source IP.

The routing tables themselves stay current through BGP — the protocol networks use to announce “these address blocks live behind me.” That’s the quiet machinery that lets any device reach any other without a central switchboard.

Public vs private IPs (and why your house shares one)

Your ISP gives your router a single public IP — your address on the open internet. Inside your home, the router runs its own private network, handing each device a private address from reserved ranges like 192.168.x.x or 10.x.x.x that never appear on the public internet.

The router bridges the two with NAT (Network Address Translation): it rewrites outgoing packets to use the public IP, remembers which device asked, and forwards replies back to the right one. That’s how a dozen devices share one address — and why every website you visit sees your router’s public IP, not your laptop’s private one.

IPv4 vs IPv6

	IPv4	IPv6
Address size	32-bit	128-bit
Example	203.0.113.7	2001:db8::1a2f
Total addresses	~4.3 billion	~340 undecillion
Status in 2026	Exhausted; kept alive by NAT and address trading	Steadily growing share of traffic

IPv4 ran out of fresh addresses years ago — NAT and carrier-grade sharing keep it functional. IPv6 solves scarcity outright, and most networks now run both in parallel (dual stack). For a deeper dive, see What is IPv4? and What is IPv6?.

Static vs dynamic addresses

Most home connections use dynamic IPs: your ISP leases you an address from its pool, and it can change when your router reconnects. Servers and businesses use static IPs that never change, so services stay reachable at a known address — the same reason a dedicated IP matters for business VPN allowlisting.

What your IP reveals — and how to control it

Your public IP exposes your ISP and your approximate location (usually city-level), and it gives websites and advertisers a stable identifier to correlate your activity. It doesn’t name you, but combined with tracking it narrows fast — our IP address explainer covers exactly what leaks.

Controlling it is straightforward: a VPN routes your traffic through its own server, so every site sees the server’s IP as the source while your real address stays between you and the VPN. Encryption covers the contents in transit. If that’s your goal, start with how to hide your IP address, and check for WebRTC leaks afterward — the one browser feature that can hand out your real address anyway.

See it yourself

Curious what your connection shows right now? Search “what is my IP”, then run traceroute (or tracert on Windows) to any website — you’ll watch the hop-by-hop path this article describes, one router at a time.