Many users surf and email totally unaware of the inner workings of the Internet. Only the brave and foolish dare go where angels fear to tread...
I'm not sure if I'm brave or foolish, but I dare peek under the hood. It's my job. And I love watching the gears turn, no matter how slowly.
One of the gears that makes the Internet run is DNS. DNS stands for Domain Name Service and it's what translates a domain name like bluewolfspirit.com to an IP address like 220.127.116.11. If it wasn't for DNS, you would have to type numbers into the address bar of your browser to surf the Internet.
I recently had the task of helping someone move their domain. I set up MT at the new site and transferred all the files. Then, I went to the site where the domain was registered and changed the name servers to point to the name servers of the new host. And, like a pregancy, all that's left to do is wait.
How long will it take? Hmmm... that depends. The name servers of my ISP think they already know where to find that address (at the old host's IP). They're going to give me the old IP and not even ask around. I have to wait until the entry gets old enough that they discard it and make a fresh query for the address.
But I can check on it.
In the command prompt, I can type "NSLOOKUP" and ask DNS servers where to find that address. If I do a simple nslookup, I'll find out what *my* ISP's name servers think is the IP for that address. This is where my browser will go if I try to get there. Once I know that, I want to know what *other* servers think is the correct IP for that address. I use the command "Server" to ask specific servers. I used the original host's DNS server and found that it pointed at the new IP address. Then I used the new host's DNS server and found that it too pointed at the new address. Well, if either of those were *my* DNS server, I could get to the page. So, now it's up to other DNS servers to update and start singing on the same sheet of music. That takes time.
So does anyone else know the right address? All I have to do to find that out is to perform an nslookup to find their name server. Then I set the server parameter and ask about the address and see if the results are for the new or old host IP address. There's also another way.
Looking Glasses for Public NAPs allows you to view the results of various commands as seen from the NAP. [A NAP is a Network Access Point - the backbone of the Internet] Most of the commands are helpful for troubleshooting BGP [Border Gateway Protocol], which is a protocol that Autonomous Systems (like ISPs) use to get your data from here to there. But, it also has a ping and trace function. From there I did a trace to the domain. Four of them traced to the old IP address. Drat. But... the fourth one allows you to run a trace from nitrous. It found it!
Now, you may wonder...what's so great about only 1/5 servers finding the new addy? I don't worry about the ones that couldn't find it. They'll eventually catch on to the change. I don't rely on the manually updated name servers (the ones from the old and new host). The entries there were entered by hand. It's the nitrous server that lets me know everything is on its way. The only way that server found it was due to an UPDATE.
Sit back and have a long, tall drink of iced tea. The gears are turning and they sound so sweet.
Posted by BlueWolf on August 1, 2002 09:42 PM