Domain Name System

In the early days of the Internet, when I was but a young man [well, I was a lot older than most of you.....], people referred to PCs and computer telephone numbers using their actual IP address. Now this was not a bad thing. It separated the nerds from the common people. Much like hexadecimal numbers. And nerds appreciated the fact that they were a special class of people, and that they knew things that ordinary people did not know. But eventually the sheer number of the IP addresses, and the quantity of PCs and computers all networked out there in cyberspace overwhelmed even the nerds.

Now this is a fascinating development. Nobody ever developed an automated name to telephone number translation service. I can't walk up to my phone and dial georgewbush, right? How come? It has been "call information" up to this very day. I had to call information first, and then hope the FBI didn't put me on some surveillance list. The reason of course is that we can give computers unique IP addresses, especially if they have to be on a worldwide network, and then figure out a name for them later. In the telephone world, names came before numbers, and they were certainly not unique, so we never had a good way to translate from a name to a number without going thru a human - an operator asking if that smith is the one on center avenue, or the one on capital avenue, or you reading a phone book and figuring it out for yourself.

So another nerd, Paul Mockapetris, came up with a system wherein a person could refer to the PCs and computers by a NAME, instead of its underlying number, and to guarantee that this name would be unique, just like the number. But the name had to be in a special format of course, called a hierarchical scheme, such as the telephone area codes, to preserve the nerdiness of the whole scheme. Nerds after all invented this whole thing, and need to feel that they still are in possession of special knowledge! So the nerds came up with a naming system, and an actual file that would be kept on each PC which translated the name into the underlying IP address. This file was called a "hosts file." Your PC still has a hosts file, and your programs still reference your hosts file every time you enter some name into your browser or attempt to send to some name. Now you can begin to see the next problem that started cropping up. As the Internet grew beyond anybody's wildest imagination, and people besides IBM and AT&T and GE had computers, the sheer quantity of the computers soon overtook even this system. Just think of the tasks involved if the Internet still used this scheme. Your precious little PC would have to have hundreds of millions of name to IP address translations, and the bandwidth of the Internet would be consumed by all these computers updating their hosts file every day.

So there had to be a better way. Well, what we do is just move a "superset" of the hosts file into the Internet, on special servers, and we invent a protocol for computers to talk to these special servers in the Internet, called "DNS servers," which will resolve names into the underlying IP addresses. This DNS hierarchy has evolved into perhaps the most critical element of the Internet. And the naming standards, and the race to see who can own "computer.com" or "ge.com" has been, and continues to be a fascinating adventure. Just think what the worldwide Internet has necessitated. Using the standard DNS servers, only one person in the world can have the name "johnloop.com." Or "shaniatwain.com." Kinda tells the human race they have been a bunch of dummies. If your name is "John Smith" you unfortunately cannot have a name of your own on the Internet. Maybe..... johnmcgillacuddysmith.com? See this page for some more info on Domain names.

Paul Mockapetris almost single handedly invented the "Domain Name System" standards and protocols to handle the naming and server hierarchy for resolving names. This is why you refer to your ISP as "bellsouth.net," for example, or "attbi.com," or "mindspring.com." Notice the apparently common sense name in the middle, like "BellSouth" and the seemingly nonsensical suffice ".net" or ".com." Jon came up with some protocols and database standards, wherein you could assign names in a certain format, such as those above, and then you could go ask this database to give you the actual IP address of the name. After all, PCs and computers only speak numbers, not names [well, the distinction cannot be elaborated upon here....]. But apparently, computers which run these databases can apparently accept a name, and return you the actual number.

So there you have it.

One of the biggest complaints that people have is with the DNS server provided by their ISP. Name queries are simple UDP DNS queries to the DNS server. If the DNS server is very busy, and late in responding to the DNS query, the UDP DNS response coming back at the customer may be dumped by the NAT/router, since it exceeded the timer which was set when the DNS UDP query went out. This can be a real headache. You may want to actually open up this port in the NAT/router to get around this problem. You can also try alternate DNS servers. The ISP may have a whole bunch of them available, you just need to find them! Another technique is to find some other friendly provider's DNS server. Maybe the local university DNS server is lightly loaded, and they have not blocked off-domain queries..... Just remember any DNS server will do, as long as it is quick, and it permits you to use it!

There are some efforts to provide some open DNS servers which are not tied to any particular ISP.. www.opendns.com is one of those efforts. Just enter their DNS servers and give it a try.

TCP/IP STUFF

WIRELESS STUFF

PC STUFF

ADSL/CABLE MODEM STUFF

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