Making Webserver on Raspberry Pi 3

Question

I am planning to host my web-server on raspberry PI 3. I just went through the process of how to create web-server on raspberry pi.

http://raspberrywebserver.com/serveradmin/get-your-raspberry-pi-web-site-on-line.html

It says basically we need to use port forwarding;

The router has an external IP address which it uses to communicate with the internet, and it has another IP address which it uses to communicate with your home network.

Let's say the router's external IP address is 88.23.65.123. The router's internal address acts as a gateway for all the devices on your network. When your PC requests data from the internet, requests are automatically sent to the gateway address, and the router forwards the request to the internet. The gateway address is usually something like 192.168.0.1.

So, my understanding is that basically, I need to get public ip e.g. 88.23.65.123 and add this IP address to my router which is connected to raspberry pi.

My question is now if I have to access my page (88.23.65.123) from outside my local area network (i.e. other connection which is connected with router and pi, is it accessible?

How to get public ip addresses? Is it free or paid monthly or yearly service?

Thanks, Jyoti Raj Sharma

Answer 1

The concept you tried to look up is "NAT" (Network Address Translation). As you said correctly, it "masquerades" the traffic from inside your private network as it travels out of it.

If you want to access your webservice from outside your private network, the most precise request you can create is "Request 88.23.65.123 on Port 80" (or another port, although 80 is default in browsers for plain HTTP). This request is delivered to your router, which is not able to do something with it, as its Port 80 will hopefully be closed (which should be the case, except there is a good reason to open it, like your scenario). You simply cannot talk to your Raspberry Pi specifically, if it is hidden in a NAT-Network.

Port forwarding solves the problem caused by NAT (which is imho a hack in itself). You basically have to tell your router "Forward every request from your outside IP on Port XX to Device YYY.YYY.YYY.YYY Port ZZ", where XX is the Port of your router being forwarded, YYY is the internal IP of your Raspberry Pi and ZZ being its Port (probably 80 and maybe 443).

In your scenario, you want your Router to forward every request to its outside IP on Port 80 (and maybe 443 for HTTPS) to the inside IP of your Raspberry Pi on Port 80 (and 443 respectively).

Static IP or Dynamic DNS: You can contact your ISP and just ask, if they offer it. It may cost additional money! You may also use services like DynDNS to get a domain which points to your Routers IP Address. Your router then contacts DynDNS after a change (or the Dynamic DNS service of your choice) to inform it. Using this, the domain always resolves to your routers IP address, even if it changes over time (this is good for testing purposes).

A serious word of warning: If you set up your router to do port forwarding, you open a gate into your private network. If your Raspberry Pi is compromised in any way, an attacker may gain access to your network and compomise other devices, so be VERY careful, if you set this up. Reading about DMZ or firewalls, may be a good idea. Keep this in mind. If your can access it from outside, chances are a malicious person can do it aswell. Make sure your network is configured properly

Edit: You may consider using a Web Hoster for a few bucks to host your website. You can develop it there without exposing your Raspberry Pi in your private network. If this is an option and your project is not about learning something regarding RaspPi specifically, I'd suggest this method. I don't know how much you know about network security, but simply Port Forwarding connection from outside to a potentially vulnerable device inside your private network is a serious threat, if not configured carefully.