Just wondering about that issue, and I may be showing my complete ignorance here....
In the Good Old Day if you looked up a web page there was one DNS query for that specific URL, and typically the relevant info was cached by your own system for a bit so when you went to the next page in that file, you already had the IP address.
Nowadays, though, each web page may include a dozen advertisements or other add-ons. And they'll be changing minute by minute.
Would this be be a noticable increase in DNS load?
Thanks
-- _____________________________________________________ Knowledge may be power, but communications is the key snipped-for-privacy@panix.com [to foil spammers, my address has been double rot-13 encoded]
***** Moderator's Note *****Since most ads are served by a separate IP address, the answer to your question is "Yes, it does increase DNS traffic by a _lot_".
It also allows Doubleclick and similar advertising providers to track your internet usage across different sites: each URL for an ad includes a code that identifies the site and page you're viewing, and the Doubleclick servers use the information to build a profile of your surfing habits and thus target ads to you based on what you've looked at in the past.
Since putting these ads on your browser depends on a lot of DNS lookups, there's a simple solution: break the DNS lookup for advertisements, so they never appear on your screen! Once you do that, you'll get both better privacy and a great boost in speed.
Your computer actually checks three places for DNS info:
- The HOSTS file on your computer is checked _first_. This is a legacy from the days of ARPANET, before DNS was deployed: each domain name had to have a matching IP address stored on each computer, and it's still in use.
- The DNS cache is checked next.
- If _both_ checks fail, your machine will perform a DNS querry to match the URL to an IP address.
Ergo, you need only "poison" your HOSTS file to prevent your browser from attempting to retrieve ads. Your computer will look at the HOSTS file, find a dummy entry, and then attempt to retrieve the ad from an invalid IP address, usually the "Loopback" address, which points back to your own machine.
There are several sources for ready-to-use HOSTS files which contain poisoned entries for most major advertising servers, but I'll refrain from mentioning them here. Google is your friend: they're not hard to find.
Bill Horne Temporary Moderator