Just to gather up everyone's comment and to put a few things in the clear
Web Server uses port 80 (HTTP), or 443 (HTTPS). Your Raspberry Pi web server will be running on either one of those common ports if it is serving web pages. Of course you can use a custom port to your need, but then to access the web pages on the raspberry pi, you need to include the custom port number on the URL (eg. www.raspi.com:8080 or if using IP address: 10.0.0.1:8080
). If you simply type in the URL with either http or https (eg. http://www.raspi.com or http://10.0.0.1
) then it will be port 80 and 443 respectively.
Your SSH session to your Raspberry Pi uses Port 22 as it is the 'default' port for Secure Shell.
For more information about reserved/common ports, please check this wiki
Now to answer your question
how can I make my server accessible to the outside world?
You need to let your Home Router (Netgear WNDR3400 as you have mentioned) to do PORT FORWARDING. By default (and for security matter), any router should have a built-in firewall that would block unsolicited request coming from outside into your home network, which is what it has done for you. For specific port-forwarding instructions for your home router, please follow this link from portforward.com
The basic idea on how to set up port forwarding:
- Login to your router
- Find your port forward page on the router
- Set up Port Forward 80, to Port 80, on the IP of your Raspberry Pi
To test if this is working:
- Open your browser
- Open your external IP address. If you don't know what is your current external IP, you can go here to check.
- If your port forwarding is done correctly, and your Raspberry Pi is serving pages correctly, you should be able to see your web pages that are hosted on your Raspberry Pi.
Hope this helps.