A LAN (local area network) connects devices in one place, like your home or office, usually with private IP addresses. A WAN (wide area network) connects networks across cities or countries; the internet is the biggest WAN. On a router, the WAN port connects to your ISP and the LAN ports to your devices.
How it works
LAN
Devices on a LAN reach each other directly through switches and Wi-Fi access points, at high speed and low latency. They share an IP subnet, typically private (192.168.1.0/24), and find each other with ARP and Bonjour. Printers, AirPlay speakers and file shares live here.
WAN
A WAN links LANs over distance using carrier networks: fiber, cable, cellular, leased lines, or the internet itself. Companies connect branch offices with private WANs or VPNs over the internet.
Your router's two sides
- The WAN side (WAN or Internet port) gets a public IP from your ISP, or an address in your ISP's network.
- The LAN side hands out private addresses with DHCP.
- NAT and the firewall sit between them.
Related terms: WLAN is a wireless LAN (Wi-Fi), MAN a metropolitan network spanning a city.
Side by side
| LAN | WAN | |
|---|---|---|
| Area | A home, office or building | Cities, countries, the world |
| Owned by | You or your organisation | ISPs and carriers |
| Typical speed | 1 Gbps+ (Ethernet), Wi-Fi | Your internet plan |
| Latency | Under a few ms | Tens to hundreds of ms |
| Addresses | Private (192.168.x.x) | Public |
Examples
- Copying a file from your Mac to a NAS at home stays on the LAN and runs at local speed.
- Opening a website goes from your LAN, through the router's WAN port, across the internet.
- Your router's admin page shows a WAN IP (from your ISP) and a LAN IP (often 192.168.1.1).
On a Mac
Your Mac's own address is on the LAN (System Settings › Network › Details › TCP/IP). Your router's WAN address is your public IP, shown by curl -s https://api.ipify.org in Terminal. If the router's WAN address starts with 100.64–100.127 or a private range, your ISP adds another layer of NAT (CGNAT or a double router).
See it in the app
LightAtom's Map draws WAN connections as arcs out to the world and lists LAN connections separately as Local network.
Frequently asked questions
What is the difference between LAN and WAN?
A LAN covers one location and connects your own devices; a WAN connects networks over long distances. The internet is a WAN.
What is the WAN port on a router?
The port that connects to your modem or ISP, often labelled Internet. LAN ports connect your devices.
Is Wi-Fi a LAN or a WAN?
Wi-Fi is a wireless LAN (WLAN). It connects devices in one place to your router.
Is the internet a WAN?
Yes. The internet is the largest WAN: a network of networks connecting LANs all over the world through ISPs and carriers.