The new service enables users to bypass their own Internet Service Provider's DNS to use Google's performance-optimized name lookup servers. Internet users constantly access DNS in the background every time they enter a URL in their browser, click a hyperlink, send email, or perform any other task that requires resolving the IP address of a given host name.
A user's currently assigned DNS server may be overburdened, slow, or even maliciously poisoned to provide bad information. That makes Google's new service both potential performance and security improvement.
Users can try the new service by entering Google's easy to remember DNS IP addresses (22.214.171.124 and 126.96.36.199) in place of their existing DNS settings, either individually on each computer they use, or centrally on their AirPort base station or other router, which will then access Google's DNS to perform all network host name lookups.
No redirection, blocking or filtering
Other free DNS services are already available, but most cover their costs by redirecting failed lookups (for mistyped or incorrect URLs) to ad supported pages that suggest alternatives. So far, Google isn't performing any such commercial redirects. Instead, the company is providing the service for free as a way to collect information about how users use the Internet on an anonymous and aggregated level.
In its Google Public DNS information page, the company states, "Sometimes, in the case of a query for a mistyped or non-existent domain name, the right [DNS] answer means no answer, or an error message stating the domain name could not be resolved. Google Public DNS never blocks, filters, or redirects users, unlike some open resolvers and ISPs."
Google's network savvy and capacity to handle huge volumes of public requests make it uniquely positioned to offer such a service for free to the public. The company itself indicates the service is being offered in order to make the web faster, as every typical web page a user loads in a browser involves several or even many DNS lookups, each of which may stall the page loading progress if it cannot be resolved rapidly.