In fact, that’s what it’s called: Network Address Translation, or NAT. When a device on your local network wants to communicate with a device on the internet, it is the router’s job to “translate” between the two types of addresses.
Each device connected to the local network has its own unique local IP address. This is that computer’s local IP address. It looks a lot like the router’s own local IP address, though the last two numbers will be different. This IP address is provided by your router. When your computer (or other device) connects to your local network, it also requests an IP address. You very likely have only one of these, and it’s assigned to your router. When the router connects to the internet, it requests an IP address, which is then provided by the ISP. Your router’s other jobĪnother job performed by your router is to manage the local network. Routers and networks confuse you? Check out How Should I Set Up My Home Network? for a popular overview. The number using periods as the separator - it’s IPv4 address 1 - is the IP address of your router.
You can see what yours is by running the command “IPCONFIG /ALL” in a Windows Command Prompt and looking for the Default Gateway address. On the local side, your router is configured to use a specific IP address: often something like 192.168.1.1, 10.1.10.1, or something similar. You can see what yours is by using several online services, or by consulting my article, What’s My IP Address? On the internet side, your router is typically assigned an IP address by your ISP when it boots up or first connects. Two different networks imply two different IP addresses. That data crosses between them is only due to the workings of your router, which is connected to both. These two networks - the internet on one side and your local network on the other - are completely separate. Be it through a wired or wireless connection, these devices connect not to the internet, but to your router, through which the internet is made available. The “local” side, often referred to as a LAN, for Local Area Network, consists of all of the devices connected to the network at your home or place of business. All traffic to and from internet sites and services travel over this connection. The internet side is a connection provided by your ISP. The router sits in-between, passing data traffic back and forth. You can think of your router as having two “sides”: one side is connected to the internet, and another to all of your computers and other devices. Routers perform many different functions, but their primary role, at least in the home, is to act as a gateway to the internet. It’s also important to know when asking questions and interpreting answers. It’s an important part of understanding how information travels between your computer and the internet services you use.