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Google Public DNS

A few days ago, Google announced the availability of the Google Public DNS. This is a replacement for the DNS service you may already have in place and Google positions this service as being more secure and faster than the average service provider's DNS response time.

DNS, or the Domain Naming System, is a name-to-address mapping service. You can think of it as dialing 411 on your telephone - you know the name of the party you are looking for, but you do not know the telephone number. The 'name' is the domain address of an entity on the Internet. For example, google.com, yahoo.com or guidelightsolutions.com. These are all human-readable names, but in order for us to access each of these, we need to convert these names into a machine-recognizable address. These addresses are in 'dot notation', such as Imagine trying to remember this number for the hundreds of websites you frequent. This dot notation, also known as the IP Address, is akin to a telephone number and uniquely identifies an entity.

In a telephone network, we simply dial 411 to 'resolve' a name to a phone number. In the Internet, we simply ask DNS to 'resolve' a domain to an IP Address. This happens, of course, blindly fast in most cases. But, the particular DNS service we use can get bogged down with requests or even directly assaulted by what is called a Denial of Service attack from malicious individuals. Google says their Public DNS service has safeguards to protect against Denial of Service attacks and that their DNS servers are part of high performance data centers and have excellent response times (i.e. they are fast).

The service is free, and all you need to do is set your DNS settings to and you can add as a backup DNS. Instructions to do so are here. But, before you do so, read on.

For individuals - especially home networks - this might make sense. For corporate environments, it is unlikely to provide much benefit.

Companies networks are typically characterized by having their own, internal DNS server(s). These servers fetch addresses from their service providers and cache them locally. Internal users already have the fastest name resolution available in most instances - they are using a DNS server within their own corporate network.

For home users, however, there are some clear advantages of using the Google Public DNS service. First, your ISP may indeed not have a very fast system handling DNS requests. Second, if you mistype a URL, many ISPs will send you to a page filled with ads and offering to help you to get the URL right (an outrageously annoying practice). Finally, Google is a very well respected name in the industry and if you ask their DNS server for a particular address, you can be fairly certain you will get the right address back.

The Google Public DNS is something you should definitely look into. It might be just what you are looking for. You can also do a quick test to see if it solves any performance problems you might have been having accessing websites. For systems administrators who need to get a machine hooked into DNS and can't remember a particular DNS's IP Address, the Google Public DNS address of is sure to be easily remembered and used when in a tight spot.


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