Improve Internet Speed by Changing DNS
by Ira Wilsker
WEBSITES:
http://en.wikipedia.org/wiki/Domain_Name_System
http://en.wikipedia.org/wiki/Url
http://en.wikipedia.org/wiki/IP_address
http://www.opendns.com
http://use.opendns.com
http://code.google.com/speed/public-dns
http://code.google.com/p/namebench 
            Most of us are blissfully ignorant about the inner workings of the internet.  We are quite happy when we turn on our computers and access the internet to surf the web or read our email.  There are several utilities that can optimize the computer's and browser's settings to maximize their performance, and I have discussed these in past columns.  What many of us are unaware of is that there is a setting that we can configure that may significantly improve our internet performance, and that is to find the fastest "DNS" freely available to us.
            "DNS" is an acronym for "Domain Name Server" (or "Domain Name System"), more commonly referred to by the moniker "nameserver".  According to Wikipedia, DNS " ... serves as the phone book for the Internet by translating human-friendly computer hostnames into IP addresses. For example, the domain name www.example.com translates to the addresses 192.0.32.10 (IPv4) and 2620:0:2d0:200::10 (IPv6)."  Simply, when the user types a web address, or "URL" (Uniform Resource Locator) in the address bar of the browser, the browser checks the computer's default DNS, and converts the website address from words to a numerical address (IP address); thus www.yahoo.com is converted to the Internet Protocol (IP) address of  209.191.122.70, a format that can efficiently be used by the internet to connect the user to the desired website.  The default DNS is typically configured for a specific internet service provider (ISP) when the user first subscribes to that particular ISP.  Normally these ISP specific DNS work just fine, but many of them are not the fastest available, and many of the ISP providers' DNS are also vulnerable to hijacking, or misdirecting the innocent user to a rogue website, opening the user to a variety of attacks or identity theft.  Some DNS are unfiltered, and let the user connect anywhere they desire, while other DNS offer selective filtering, which can block access to undesired websites, such as pornography and phishing (identity theft).  Many adults are perfectly satisfied being able to connect where they want, but families with children and others may want filtered access, and some DNS provide that service.
            What is possibly the largest and most widely used alternative DNS is OpenDNS (www.opendns.com).  Anyone can configure his computer to use OpenDNS instead of his ISP's default DNS, and may experience faster and more secure internet connections.  The basic OpenDNS services are free to individuals, and enhanced commercial (pay) services are available to everyone.  Thousands of businesses, government agencies, K-12 schools, college and universities, non-profits, and others utilize the commercial OpenDNS services.  OpenDNS says that, " OpenDNS is the leading provider of free security and infrastructure services that make the Internet safer through integrated Web content filtering, anti-phishing and DNS. OpenDNS services enable consumers and network administrators to secure their networks from online threats, reduce costs and enforce Internet-use policies. OpenDNS is used today by millions of users and organizations around the world."  A comparison of the free and commercial OpenDNS services is available at www.opendns.com/start.  The basic free service includes selectable web content filtering, phishing (identity theft) protection, defense against botnets, and can correct many "typo" errors which can protect the user from connecting to rogue websites with close web names.  The paid service with additional features and protection is very reasonable at about $10 per year for a family (5 computers), and $5 per user per year for commercial (business) accounts.  Special pricing is available for K-12 schools.
            For those who would like to change their default DNS to OpenDNS, easy to follow instructions are provided by OpenDNS at use.opendns.com or the actual IP address of 208.69.38.205. OpenDNS is compatible with almost every operating system, and simple directions are provided for Mac OS X, Windows 7, Windows XP,  Windows Vista, Generic Routers, Linksys Routers, Netgear Routers, and D-Link Routers.  One warning; although OpenDNS is extremely reliable and trouble free, I strongly recommend that users write down their default ISP information, before changing the DNS settings to OpenDNS or any other nameserver.  It might also be a good practice to print the OpenDNS instructions just in case the current DNS used by your ISP becomes unavailable, and then you can easily switch to OpenDNS and probably be back online in seconds.  Anyone can change his default DNS to OpenDNS by using 208.67.222.222 and 208.67.220.220 as his default DNS.
            There are several excellent DNS available to the typical user, and Google is now offering DNS services to anyone who would like to use them with its Google Public DNS service (code.google.com/speed/public-dns).  With all of the necessary information online including benefits and setup instructions for almost every operating system (code.google.com/speed/public-dns/docs/using.html), Google Public DNS may be a good choice instead of the default DNS provided by your ISP, and generally offers better security and protection from purloined websites, as well as better speed and general performance than the ISP provided DNS.  Google Public DNS offers many of the same benefits of OpenDNS, including the integral enhanced security features.  Google Public DNS uses the IP addresses of 8.8.8.8 and 8.8.4.4 which anyone can set as his default and freely use.
            There are many other DNS available to users, and Google provides a free open-source  utility it calls "Namebench" that can automatically test the available combinations of DNS from the user's computer, and determine which ones provide the best overall performance for the specific user.  This free utility is available from Google at code.google.com/p/namebench, and runs on Windows, Mac OS X, and UNIX.  I downloaded and ran the Windows version of Namebench from my Windows 7-64 computer, and in about five minutes Namebench tested hundreds of DNS combinations, and found a combination that was 31.8% faster than the DNS provided by my ISP.  In my case, OpenDNS-2 (208.67.222.222) provided the fastest service, with Internet America FDDI-2 US (207.158.92.18) recommended by Namebench as my secondary DNS.  Each user should run Namebench on his own computer to determine the best combination  for his machine, as results will vary from machine to machine.
            While all of this DNS business may sound complex, it is really very easy for users to change their DNS settings to a safer, more secure, and faster connection.  While OpenDNS and Google Public DNS are both fast, excellent, and reliable, and either may be a good choice for a default DNS over the one provided by the ISP, I would recommend that Google's free Namebench be run to really determine which DNS combination is best for a particular computer.  Since ISPs and the other providers of DNS services are subject to the rapid changes extant in the internet, it would be a good idea to periodically rerun Namebench to verify that the currently selected DNS are still the best combination for your computer.  Always remember to write down the current DNS settings before changing them, just in case you might ever want to go back to the original settings, but this is not likely with OpenDNS, Google Public DNS, and the results from Namebench.