So, first off, what is DNS and why do you care if it’s fast? A crash course in dns is that it changes a nice, memorable name like, oh say, danklassen.ca to it’s actual IP address (209.20.65.249 in this case). Think of it as flipping through the phonebook to find out somebody’s phone number.
Now, as you are browsing the web sometimes you may notice that it can take quite a while for the page to initiate a connection with the remote server. This can sometimes be caused by a slow response from a dns server so it takes a while for your browser to figure out who to ask for content. Imagine you’re running a server and you are sending out a few thousand emails an hour, as well as pulling in content from multiple sources, and doing reverse lookups on numerous IP addresses. Any slight delay will add up to huge latency over time, and DNS lookups can be quite costly (time-wise).
OpenDNS is a free service that has a number of servers around the world. They’ve created an amazingly reliable (and quick) network of DNS servers that are free for anyone to use. To set this up on any linux box:
sudo vi /etc/resolv.conf |
and enter the lines:
nameserver: 208.67.222.222 nameserver: 208.67.220.220 |
And that’s it. No really, that is all you need to do.
As an added bonus, they provide you with an easy cache check to see what a domain (or sub-domain) currently resolves to. If you have recently updated, you can force OpenDNS to pull down the latest zone file with your changes, something that can take hours, or even days on other name servers. One thing to realize though, is that once you start using OpenDNS, even non-existent domains and subdomains will resolve to an IP, usually 208.x.x.x, but is something to be aware of. If you don’t know how this could effect you, don’t worry about it.
For home/corporate users, they have phishing philtering, adult site blocking, customizable domain black/white listing, etc. The way they seems to be supporting their financial costs is through serving ads when you type in a domain that doesn’t exist (ie: for some reason, google hasn’t seen fit to set up danklassen.google.com)
Hey, if they can handle 6.3 Billion (yes, that’s a B at the front) dns requests every day, I’m pretty sure they can handle your needs.
Tags: dns, server admin, web service