| You may not know what a DNS is, but every time you surf on over to a Web site by typing in its name, you are using a DNS to get there. DNS stands for Domain Name Server. Basically, all a DNS does is convert the address name you typed into a series of numbers that is the actual numerical location of the Web site you wish to see. Those numbers are the Web site's Internet Protocol address. So when you type in a Web site's name, that name is sent to the DNS, which in its simplest form is a database of Web site names and their corresponding IP addresses. When the DNS finds a match to your name query, it passes along the corresponding IP address to be located, and your browser displays the corresponding Web site. Complex process Please note that this is a highly simplified explanation of a complex process, but it's really all you have to know when I tell you that you don't have to use the DNS your Internet service provider (ISP) assigns to you. While part of an ISP's service is to provide you with a working DNS, you actually have a choice. But why would you want to change the one you already have? Well, as with most everything, some DNS services are better than others. What makes a DNS better? Speed is one thing, safety is another, and how often its database of names gets updated can certainly be important, too. And anything else it can do to further help expedite your getting to the Web sites you want, is gravy. That leads me into telling you about OpenDNS. First and foremost, OpenDNS is a free service, so that's one enticement. According to OpenDNS, it's also faster because its DNS runs on a high-performance network that's geographically distributed within the United States and serviced by several redundant connections. That's somewhat nebulous, and you may or may not be aware of any speed differences. But DNS access speed is just one of many factors that make your Internet connections work the way they do at any given moment. What are more quantifiable are the safer and smarter elements of OpenDNS. In addition to keeping a very large and speedy database cache of IP addresses, OpenDNS keeps track of their legitimacy. Warning issued So if you attempt to surf on over to a malicious Web site, such as one set up for a phishing attack, OpenDNS will warn you of the site's illegitimate nature and prevent you from going there. That's a nice feature not normally found within a DNS. The other cool feature is OpenDNS' ability to spot typos in a Web site address and correct it for you automatically. For example, if you typed in craigslist.og, OpenDNS would correct the error and take you directly to craigslist.org instead. Changing where your computer goes when it needs a DNS lookup is easy to do. Of course, be sure to first write down the DNS IP addresses you are replacing before you make the changes. Depending on what OS you use (Windows, Mac, Linux, etc.) simply replace the DNS IP addresses with the ones for OpenDNS that are 208.67.222.222 and 208.67.220.220. There is no software to install, and you can switch back at any time. Bottom line is that you have nothing to lose and everything to gain by giving OpenDNS a try. Check it out at www.opendns.com. 责任编辑：米尊 |