Making your Computer Accessible from the Public Internet

A video tutorial series for troubleshooting remote access to server-based applications

What you need to do to allow connections to your computer:

1. Make your router forward connections to the computer
2. Set up your firewall so it does not block connections
3. Address and connect to your PC

Make Your Router Forward Connections to the Computer

Router and NAT configuration by port forwarding

For most people, their NAT router is the biggest stumbling block to getting connections to their server-based application. This tutorial will teach you why that is the case, and what options there are for getting around it, including UPnP and port forwarding. Read the video text here.

Useful Terms: NAT router, UPnP, Port, TCP, UDP, LAN, WAN

Additional Resources:

• Instructions for port forwarding on almost any router ever made, along with detailed information about most of the other topics covered on this page.
• A list of common port numbers
• Is UPnP enabled on your router? Log in to your router similar to if you were going to port forward (shown in the tutorial). Look for UPnP settings under headings such as UPnP, Applications, Port Forwarding, or Virtual Server. Once found, you can enable UPnP from there. Remember, if your router doesn't have a UPnP setting, you will have to port forward.

Set Up Your Firewall So It Does Not Block Connections

Configuring your system and third-party firewalls

It is a firewall's job to question any incoming request to your computer. Therefore, it is up to you to tell your firewall which requests are legitimate. This tutorial will remind you where all your firewalls are, and will give basic instructions on how to create exceptions for your application in those firewalls. More detailed firewall resources are listed below. Read the video text here.

Useful Terms: Firewall, TCP, UDP, NAT Router

Additional Resources:

For Windows OS Firewalls:

• Windows XP
  How to manually open ports in Internet Connection Firewall in Windows XP
  Using Windows Firewall
• Windows Vista
  Open a port in Windows Firewall
  Allow a program to communicate through Windows Firewall
  Add an exception in the Windows Vista Firewall
• Windows 7
  Allow a program to communicate through Windows Firewall
  Open a port in Windows Firewall

• Mac OS X 10.4 Tiger
  Creating an advanced IP firewall rule
  Setting advanced firewall options
• Mac OS X 10.5 Leopard
  About the application firewall
  Setting firewall access for services and applications
• Mac OS X 10.6 Snow Leopard
  Setting firewall access for services and applications
  Using the Firewall pane of Security preferences

Below are links to several personal firewall applications. While it is clearly not a comprehensive list, you can find many resources online by searching the firewall's website and checking their support files or contacting them directly for help creating a rule.

• ZoneAlarm
• Sunbelt
• Emsisoft Internet Security
• Norton Internet Security: Search the support topics according to your product (Norton Internet Security), the version year, with the subject "firewall." You should see a link for creating rules in the firewall for that specific version of Norton Internet Security.
• Outpost Firewall
• Kaspersky
• Agnitum: Under "Download documentation," locate your firewall product and download the Userguide pdf. Within the pdf, look for a chapter called "Managing Applications Network Access" under the Managing Network Connections chapter.
• Comodo

Address and Connect to Your PC

Handling static and dynamic IPs, and domain names

Useful Terms: IP Address, Port, ISP, DNS System

Additional resources:

• Find out your public IP address
• Instructions for finding your private IP address, complete with a video
• A guide for setting up a dynamic DNS

STUN

Some VoIP applications use a method called STUN to keep a line of connection open. This tutorial explains what STUN is, and how much control you have over it. Read the video text here.

Useful Terms: STUN, UDP, NAT Router

Hairpinning Issues with STUN Note that sometimes when testing your IP from within your network you may not be able to connect to it. This just means your router does not 'hairpin' packets. To connect to the server from within your own network you need to use the private IP address (and private port) of that server. From outside the network though (i.e. across the Internet) you can use your public IP address (and public port) to access it.