CCNA Routing & Switching:External Ports Of Cisco Routers
Description
Port Forwarding
From Inside of Your Network
Here’s a map of a simple home network.
map intranet fin-01
As you can see, you’ve got three computers with unique IP addresses all connected to a router. You can easily access the other computers, but when they all access the internet, they go through the router. The router has an IP address that’s relative for you network, but it also has an external IP, one that it uses when interacting with things outside of your network. Whenever these computers make a request towards the internet, they all use the same IP – 127.34.73.214 in our example. Simple requests, such as loading web sites, are automatically handled by the router and are sent to their appropriate places. It’s not too difficult because each computer starts with a unique request, so it’s not hard for the router to figure out where things should go