Using EduVNC with home NAT/Router
From EduVNC
Contents |
Connecting to EduVNC through a Home Routers and NAT
Many high speed connections are protected by a router or NAT. Usually this is a box provided by the DLS, Cable, FIOS provider which allows multiple computers to share an Internet connection. This box provides a Router, NAT, DHCP server, and a switch all rolled into one box. If you have one public IP address and more than one computer or wireless connection you have one of these boxes. These boxes hide all the computers in your house so they appear as one computer on the internet. To use EduVNC with a computer behind a home router a few extra steps are required.In order to directly connect to the computer and port you are running EduVNC on you'll need to enable Port Forwarding. You'll also need some way to find your home's IP address when your not there.
Enabling Port Forwarding
What you will need to know
Before you start lease get these 3 pieces of information and have them ready to use.
- IP address of the Router
- run 'ipconfig' in a command prompt window
- typically the gateway address
- IP address of the computer running EduVNC
- run 'ipconfig' in a command prompt window
- find the ip address (usually 192.168.x.x, 10.x.x.x, 172.x.x.x where x is variable)
- the gateway and ip address should share the first 2 or 3 numbers. This is normal and means the computers are on the same network.
- Port you have EduVNC configured to use
- Get this from the EduVNC configuration for the service you want to access from the internet.
Generic Instructions
Port forwarding is the process by which you tell your home router to forward internet connections on a certain port number to a certain computer inside your network. The process varies by router model so you might need to check with the manufactures website for more precise instructions. Here are some common manufactures guides: Netgear, Linksys / Cisco
Most home routers can be configured through a web based interface. This means you can use a web browser to change the settings on a web page. The web page is is accessed by opening a browser and visiting the IP address of your router (which you should have gathered already). To do this open your web browser and in the address field (the thing that says http://, not the search box) put http:// then the address of your router. So if your router has IP address 192.168.1.1 then you put would put http://192.168.1.1 then press enter. This will usually bring up a password prompt or login page. If you know (or have changed) the password and/or username go ahead and enter it. If you've never done this before their are a few common defaults for the username and password below or you can look it up online here.
- Common default usernames
- [leave blank]
- admin
- root
- user
- Common default passwords
- [leave blank]
- admin
- password
Once you get logged in you'll see a web page with the routers settings. This is where things really start to differ between routers. Usually the pages are divided into sections either with a sidebar on the left or tabs on the top (or both) signifying major sections. Your going to look for port forwarding in the one which seems to have to do with the firewall or nat functions. Usually its in the advanced or firewall settings sections, but, if you can't locate it after a couple of stabs try systematically searching all the apges. You should eventually find the right page labeled port forading, single port forwarding, application forwarding, or simply forwarding. This page will minimally have place where you put a port number and an IP address that you will forward it to. Many routers also allow you to specify the protocol (TCP, UDP or both), give it a friendly name (like EduVNC), and specify the port on the IP address you want to forward to. Some pre-fill 3 of the destination digits and only allow you to enter the last and others you ahve to type the whole address. But you want to put the port of your EduVNC service and your computer's IP address in these boxes. If your setup does not allow you to specify the port for the destination IP you must put the port as the EduVNC port. If it does you can configure the incoming port differently, but its probably easier not to. Once you have it configured hit save (and apply). When saving the router may reboot as that is how many routers activate settings changes. If your on wireless that might disconnect briefly, just wait for the router to reboot and you'll reconnect. Your all set
Testing and Troubleshooting
You can test your port forwarding by visiting http://you_public_ip:you_eduvncport in a web browser. So if you public IP was 4.4.4.4 and you EduVNC port was 80 then http://4.4.4.4:80 should show the EduVNC login page. Some routers won't let you 'loop back' to the router from inside the network behind it so you may have to test from another internet connection (like a cell phone [not on your wifi!] or a friend's house).
Common Problems
IP of computer changes
If you set up your port forwarding and it was working, but breaks your desktop probably changed IP addresses. Run through the guide again and alter the IP address to the new one. You can prevent this by settings a static IP address if you know how, but that is outside the scope of this guide.
Internet IP of router changes
From time to time your router may change IP addresses, this is normal on most home connections. You'll then have to find the new IP and start using that to connect. To prevent this from happening you can pay your ISP for a static ip address (one that doesn't change) or use a Dynamic DNS service to associate a host name with the current address. The Dynamic DNS services are usually free for home use and give you a host name like mycomputer.dynamicdns.com to use instead of the IP address. You then have to configure your router to automatically update this host name when it switches addresses which is outside the scope of this guide, but should be well documented by the dynamic DNS provider.
