Explain to me the Domain Name System

I’m trying to get a new Mac up and running, and I’m having a problem. If I use the IP numbers in Explorer, it works just fine, but if I try to use a URL, I get a “Cannot find specified server” error. So this is probably a DNS problem, right? I’ve got DNS numbers from my provider, but they don’t seem to be working.
So my real question is this, in two parts: A) How does the DNS system work, how is that organized and who is in charge? and B) Do I have to use the numbers that my provider gave me, or are there other numbers I can try to see if they work?

Thanks in advance.

Have you talked to your ISP about this problem? You should be connecting to their DNS which is getting info from other DNS’s about which domain goes with which IP.

I don’t know how to ping from a Mac but if you can figure that out, try pinging a domain name. If you can ping a domain name then your browser may be configured incorrectly.

InterNIC FAQ on the Domain Name system

To test out the domain in the URL, go to www.samspade.org and enter it there. If Sam Spade can get to it, you should be able to as well, otherwise there’s a problem with your browser and/or ISP.

DNS stands for Domain Name Service. Basically it’s job is to translate domain names into IP addresses, obstensibly because IP addresses are much harder to remember than domain names.

There is a governing body presiding over domain names (I can’t remember who’s in charge these days) and they maintain a master DNS list. Several times a day, this master list is pushed out to several propogation servers. Each of these propogation servers allows other DNS servers to connect to it and download the master list. Generally, any change of DNS info takes between 12 and 48 hours to fully propgate.

When you sign up for service with an ISP, they will give you the IP addresses of one or more of their DNS servers. Usually, at a bare minimum, an ISP will have two DNS servers, a primary and a secondary. If you had the addresses of other DNS servers, you could use those when setting up your TCP/IP settings, but you’ll generally get improved performance by connecting to your own ISP’s DNS servers because they will be on the same network which which will decrease latency of DNS requests. I think there are several free DNS servers that you could connect to in a pinch, but I don’t remember what their addresses are. You should do a search on google (or your search engine of choice).

DNS is actually a lot more complicated than I’ve made it out to be, involving some fairly complex caching algorithms to reduce internet traffic. You can find out more about it here:

http://www.geocities.com/Heartland/4394/work/dns.html

DNS and ISPs can get a bit messed up. 2 of the 3 DN servers fed to me by my ISP are D.E.A.D dead. Have been for a year. What’s more, the only live one is last on the list so that any PCs using DHCP* look up server 1, wait, look up server 2, wait, look up server 3, at last, pages! So I have to manually set just the live one as DN server for my machines, which is a pain for the laptops who sometimes travel elsewhere.

  • Regarding DHCP. This is a “get IP address (and DNS) automatically” system that works on all suitably set up platforms, including Macs. Try Googling on DHCP Macs, etc. or ask in a Mac oriented forum.

It’s governed by Network Solutions, Inc. currently.