DNS Propagation

Dennis Faas's picture

Well, it finally looks like infopackets.com has completed its journey over to its new web server. The entire process (from start to finish, including changing registrars) took about 60 days to complete. Most importantly, my own personal computer is finally connecting to the new web server.

The hard lesson learned: while most web service providers are eager to say that a change like this "should only take 72 hours to complete", just remember -- anything that could go wrong probably will, and expect the worse case scenario.

OK, I expected that.

But I think I got hit with worse than that worse-case scenario! A DNS error was responsible for rejecting approximately 8,000 delivered issues of the Infopackets Gazette, when the last issue was released.

DNS is an acronym which stands for Domain Name Service. Every time a web site name is entered into a browser, DNS is initiated and the result is used to make an actual connection to the destination web server through the use of an IP (Internet Protocol) address. In this case, infopackets.com resolves to the IP address, which points to our new web server in Aurora, Illinois.

Do a DNS test for yourself: For Win 9x/ME: Click Start -> Programs -> MS-DOS Prompt; for Win 2k/XP: Click Start -> Programs -> Accessories -> Command Prompt. Once the window is open, type "ping www.infopackets.com" (no quotes). The result should look something like this:

  • C:\>ping www.infopackets.com
  • Pinging www.infopackets.com [] with 32 bytes of data:
  • Reply from bytes=32 time=94ms TTL=49
  • Reply from bytes=32 time=78ms TTL=49
  • Reply from bytes=32 time=78ms TTL=49
  • Reply from bytes=32 time=78ms TTL=49
  • Ping statistics for
  • Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
  • Approximate round trip times in milli-seconds:
  • Minimum = 78ms, Maximum = 94ms, Average = 82ms

So there you have it -- a DNS resolving right in front of your eyes. Magic!

Alright. So now that we know what DNS is -- what is DNS propagation?

DNS propagation refers to the process of updating all DNS systems on the Internet. Think of DNS as an index which points to a list of web sites. In the example above when infopackets.com was ping'ed, a DNS system responded with the appropriate IP address listed within its system.

Of course, not all DNS systems update at the same time.

DNS is a propagating service which can be compared to a line of construction workers passing a pale of dirt from one to another, until it reaches the end of the line (or "the end of the Internet" -- is there such a thing?) In the case of infopackets.com, it took 60 days to "pass the bucket" to flush an old DNS setting which was still pointing to the old infopackets.com web server. While this old setting only effected about 5% of our web visitors, it made repairing any web site errors difficult because any change was being done so blindly. Don't forget -- my personal computer was still pointing to the old web server.

In the case of the last issue of the Infopackets Gazette, my old web host provider cancelled the account (as I ordered them to) and the old server ceased to exist. In the mean time, some DNS's were pointing to absolutely nothing. This happened at the exact moment as the last issue of the newsletter was being sent out. Great timing!

Why is that a problem, you say?

Whenever an Infopackets Gazette issue is sent out, it needs to be delivered to a mail server. Before most mail servers will accept an email message, it must do a DNS lookup on the person who is sending the email. Some mail servers will reject email if the sender claims to be from an organization or web site (infopackets.com) that does not exist (even temporarily). In this case, infopackets.com did not exist because the old web server account was disabled -- so all the delivered emails bounced back.

No big deal, right?

Maybe not for you! I was the one who had to clean out 10,000 or so emails that got "jammed" on the new web server. Not an easy task! At the same time, I was unable to receive the many emails that I usually receive whenever an new issue of the Gazette is sent out. And believe me, the last issue prompted many Infopackets Readers to email me regarding whether or not Grisoft Anti Virus had an auto-update feature!

When I find the time, I expect to get the Discussion Board set up. In fact, I'm going to try and find an add-on module that will allow for discussion following each main article / guest article issue of the Gazette. That may mean ditching the previous Discussion Board.

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