Ouch! That sounds painful! Not really. All it means is turning a wireless router into a wireless access point and switch. Why would you want to do that? Because you want to rum a server and what you’re doing doesn’t work.
Routers
A router’s sole purpose is connecting more than one device (computer, PDA, wifi-enabled cell phone, game) to a single internet (IP) address. This is called the external IP address. What other kind is there? I’m glad you asked. No two devices on one network can have the same IP address. Packets (that’s how data is organized, in packets of bytes – think of a packet as an envelope to hold a small bunch of data) are sent with an address header – where the packet came from and where it’s going. The “where” is an IP address. So if two devices on the internet had the same address, where would it go? That’s why every device – in a single network – needs its own IP address. Devices in different networks can duplicate addresses because, as you’ll see, it doesn’t cause any more of a problem than two different companies sharing a suite number – in different buildings.
Internal address
Your computer, if you’re “behind” a router (you have a router between your computer and the internet), gets an internal IP address from the router. This is normally in the range of 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255 and 192.168.0.0 192.168.255.255. So how does this internal address become the external address? The router does what’s known as “network address translation” – NAT. It assigns address “a” (let’s say 192.168.0.2) to computer B. When computer B connects to a web server and asks the server to serve it a page, the router notes that request down, so that when the page comes from the server, the router can change the “to” address (it’s the external address, which is all the server can see) to that of computer B, 192.168.0.2, in this case.
If you run a server on your computer (a web server, a game server – any server), you want people to be able to connect to that server from the world outside your router, so you give them your external address (or use a free dynamic DNS service, like DynDNS or No-IP so they only have to remember something like joesxbox.noip.net) and they connect to … err, they can’t connect to your server. They connect to your external address on, say, port 1234 (the port number is usually determined by the type of program). Your router has nothing listening on port 1234, so it ignores the connection request.
Port Forwarding
This is where port forwarding comes in. You tell the router (on its port forwarding or virtual server page) to forward port 1234 to internal IP address 192.168.0.2. Now, when a connect request comes in for port 1234, the router looks in its forwarding table, sees that port, forwards the request to computer B, and everyone’s happy. (If you want to know how to set your router up to forward the port your server program needs, go to PortForward and choose your router. You’ll be taken to another page, where you can choose the program you want to forward ports for. That will take you to a page of screen shots of your router, with instructions. Don’t ignore the Static IP Address link at the top, if there is one. A properly designed router will not forward ports to a leased address.
Emasculation
So what’s this about emasculating your router? Go back to that first link and look for your modem. If it’s listed there, it means that your modem is also doing address translation (this type of modem has a full router inside it), and forwarding a port through 2 address translations seldom actually works. You need to get rid of one of those address translations. (Don’t actually do anything until you’ve read all of this. You’ll lose internet connectivity at one point, and get it back at the next step, if you’ve already read what the next step is.)
Connect to your router with your browser (the same way the router instructions tell you to – put in the proper login and password where needed) and look around for the letters DHCP. That’s the server (in your router) that assigns an internal IP address to a device that connects to the router. But the modem would do the same thing – if the router allowed the device’s request to get to the modem. It doesn’t, it does NAT itself. So you need to do 3 things – disable the DHCP server in the router, connect the modem to one of the computer jacks on the router (forget the WAN or Internet jack – you’re not going to use it) and forward the port in the modem, not the router. (If all 4 jacks are filled, keep reading.)
So …
Disable the DHCP server in the router. (It’s usually a check box or on-off radio buttons), turn the router off, remove the wire coming from the modem and plug it into one of the (usually 4) computer jacks and turn the router back on. (You’ve already read the Static IP Address page, as it relates to your modem, right? Maybe even printed it out?) Change the IP address in your computer to one that will work with the modem (same subnet, out of the DHCP range of the modem). If you have any questions at this point, don’t change anything. Read the PortForward page for your modem, then join the forum (it’s free and spamless) and post your question or questions in the relevant area(s) of the forum. The reason the moderators are there is to answer questions. If no one asked questions, they would have no reason to be there (other than the nifty cap).
Search the forum first, though, to see if they’ve already answered that question for your modem. There’s nothing more annoying than to see the same question asked in the same way 5 times every day.
Once you’re all set up, and can access the internet with no problem, forward the port(s) you need in the modem and people should be able to connect to your server.
Emasculation? That just refers to turning off the DHCP server in the router and hooking it up backwards. If you really needed all 4 computer connections, think of using wireless for at least one of the computers. Or buy a switch – that’s just an intelligent “multiple outlet” box. You can connect 4 or 8 or 16 or … computers to a single cable, as long as something down the line from the switch is doing NAT. Some one thing, not 2 or 3 or 10 – if you’re running a server. For connecting to the web and reading your email, running more than 1 address translation is fine (unnecessary, but fine).
I hope this helped you in some way.
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