Accessing ethernet Arduino on LAN from internet?

Projects Networking, Protocols, and Devices
2

You need a bit more than just port forwarding :wink:

  1. In order to be able to connect tou your home network you need to know what it's public IP address is. Your Internet service provider likely a has assigned a public, dynamic IP address via DHCP to you, so each time your router disconnects and then reconnects you may have a different IP address. So yo can either talk to your ISP and ask for a static IP address, which is likely to cost you more money, or you can remedy that by registering at dyndns.com, or no-ip.org. Then you have a name associated with your dynamic 4-byte IP address, for example myArduino.no- ip.org, that you can use instead of the 4-byte IP address.

  2. Likely your home network assigns a private, dynamic IP address also via DHCP to the devices in your home, including your Ethernet, or WiFi enabled Arduino. It depends a little on your routers abilities, but, yes, you could port- forward port 80 (http) to your Arduino borards IP. Some routers can do this per device name so regardless of what private, dynamic IP address they have assigend to the device it goes to the right device. Or you can reserve a static IP address in your Router for your Arduino.