Today’s topic is our wireless life and what makes it so difficult to manage. You would think that since just about everything we do these days increasingly depends on radio waves and wireless communications, the powers that be would want to make it easy for us. You’re dreaming, right? The problem is that not only does every player want to be paid, some players don’t want to play fair. First there are those who provide the wireless services for us. They rightfully should be paid to set up and maintain the services we get. On the other hand, some of them simply charge unnecessarily high fees for the fault prone services they provide. Some want to get all for nothing. They will try everything they can to circumvent the measures set out by the service providers trying to get their fair(?) pay. That’s one thing. Then there are those discussed earlier who want to break into other’s banks and homes to take what they want.
This so far sets the stage. Oh no. I see that this is going to be difficult. In the end it goes back to those ones and zeros I talked about a long time ago: digital signals and now dollars and cents. On the digital side, you will need to know in very simple terms how the world wide web works. I mean how information travels through the air or through wires from one place to another. Have you ever thought about the Web part of world wide web? It’s a highly organized mish mosh of threads. The great puzzle in finding a way to make the web work was how to ensure that data travel safely from one point to another. Easy? What if one of the wires breaks or an electrical storm messes with the radio signals? There are things called domain servers spread around the globe. Back to the dictionary now. Two confusing terms: web address and IP address. Although they look nothing alike, they refer to the same address. It’s like saying let’s go to Douglas’s house for dinner, and let’s go to 3845 Ver Halen Ct., Some City California for dinner. The web address is the human readable/friendly address. The IP address is a grouping of numbers that refers to the location in the world of the web that you are located. Domain name servers are responsible for keeping all of this straight. There are data bases out there around the globe that keep track of these things. It’s like a phone book. In a phone book you can find a business or a person. A phone number is associated with that business or person. What if you have only the number and want to find out whom it belongs to? You use a reverse look-up directory. Well, the web uses exactly the same thing. A third term is domain name. That is the part of the web address that comes after the first part. For example, http://www.quantumnight.org. Quantumnight.org is the domain name I have purchased or rented. On my home network, my IP address is 192.168.2.103. That IP address belongs to a special group of addresses called private network addresses. They are only recognized in local networks such as a small business or home.
The next thing we need is a way for you or your computer to see the outside world. You need access to those phone books. If you don’t have one of those, it would be like landing in Pleasantville and trying to call for pizza. It ain’t going to happen without some help! The thing that provides the phone books for you is a DNS. That is a Domain Name Server. It might look exactly like your IP address. My local one is 192.168.2.1. It gets its information from Earthlink. Unless you have a your own server, you would only use or need the DNS addresses from your ISP (Internet Service Provider). You would almost always have three DNSs available. Why? The world wide web and fault tolerance. If one goes down in South Africa, one in Ireland will take over. You’ll probably never know what happened. If your connection to the Internet is good, but you can’t go to http://www.google.com, your DNS has a problem. The test is to enter a known good IP address–remember the number not the name. If you get there with that, your reverse lookup is not working.
The next thing is you. It’s always about you, isn’t it? You, or your computer, needs to be assigned an IP address to talk to the world. Actually, that IP address is assigned to your router or the device that connects to the Internet. Do you want to spend time talking to someone you can’t see or smell? You can only exist on the Internet when you get a number. “No I’m not a number, I’m a human being.” Sorry, that’s so last century. Let’s say you have a router, and your brother is on the net, but you can’t get on. It’s a router for crying out loud. If everything seems OK, you might not be getting an IP address from your router. Routers use something called DHCP. That stands for Dynamic Host Control Protocol. Oh no, I told you this might get tricky. Usually your ISP will be reluctant to give out more than one IP address. What DHCP does is break away from your ISP assigned IP address, and start assigning private IP addresses. Your router will then channel all Internet communication through the official ISP assigned IP address. Remember the range of private IP addresses are not seen outside your local network. Your ISP cannot see it. It’s kind of like a funnel. You can pour three bottles of beer at the same time into it, but it leaves through a single hole. I know that’s a pour metaphor.
You might ask how your ISP or anyone else might come to know several people are sharing a single Internet connection. The answer is pretty simple. Every network adapter or device that touches the Internet has a unique Media Access Control address, or a MAC address. This is true whether it’s a USB wifi adapter, an ethernet adapter, or anything else that is used to put you on the web. When you wake up and turn on your computer. It turns on your adapter, which in turn talks to the device that talks to your ISP. Your ISP knows the device they gave you to go on the web. They also know you must connect to that via some other adapter. The count now is two MAC addresses. One of those represents your computer, the other the ISP’s device whatever that is. It is most likely the case that your broadband service is always on. The ISP’s device records or remembers your computer’s MAC address. This is a point of failure, so to speak. You unplug your computer from the modem (dial-up, cable, or dsl), and then connect your sister’s computer. Her computer will by definition have a different MAC address. Your ISP sees this and will not assign a new IP address to go with that new MAC address. Keep in mind what I said earlier that to get on the Internet, you must be assigned an IP address. You could plug YOUR computer back in and be fine. So what’s a simple fix for this situation? You must cut the power to your cable/DSL modem–pull the plug. This will force the modem to renegotiate its hand shake with your ISP, which will in turn accept as legitimate whatever device and its MAC address that is first found.
This is where the router comes in. If your router’s MAC address is the first one found, you’re done or good to go. All new MAC addresses are hidden behind the router. And the router assigns private IP addresses, which are also hidden from your ISP. The official IP address assigned to your router is all that’s seen, and the router’s MAC address of course.
Another point of failure is where two or more devices are claiming to have the same IP address. I’ll give a quick example: My ZyXEL DSL modem has a default private IP address which happens to be 192.168.1.1; my Belkin router by default uses the same IP address. I had to change my Belkin’s address to 192.168.2.1 to avoid conflict. How would you like to be further confused? My ZyXEL modem actually has two IP addresses. You must have an IP address to get onto the Internet right? If a private IP address is invisible beyond your private network, what’s the use? Well, your ISP assigns a true public IP address to their device, but usually this IP address frequently changes. It could be different each time you turn on your computer. It is easier for your computer to talk to the modem with an unchanging IP address, and let the modem take care of the rest. In case you’re wondering, my current public IP address is 220.127.116.11 assigned to my modem; my private address is 192.168.2.103. That’s for my router’s eyes only, and changes only if and when I want it to.
There’s so much more to this topic. I haven’t yet talked about the keys and encryption usually required to negotiate a connection with wifi networks. That is for another day. For now we have IP addresses, MAC addresses, private and public, modems and routers. Till later, keep the ethernet lights flashing.