Google DNS

Why Google Public DNS?

As web pages become more complex and include more resources from multiple origin domains, clients need to perform multiple DNS lookups to render a single page. The average Internet user performs hundreds of DNS lookups each day, slowing down his or her browsing experience. As the web continues to grow, greater load is placed on existing DNS infrastructure.

Since Google’s search engine already crawls the web on a daily basis and in the process resolves and caches DNS information, we wanted to leverage our technology to experiment with new ways of addressing some of the existing DNS challenges around performance and security. We are offering the service to the public in the hope of achieving the following aims:

Provide end users with an alternative to their current DNS service. Google Public DNS takes some new approaches that we believe offer more valid results, increased security, and, in most cases, better performance.
Help reduce the load on ISPs’ DNS servers. By taking advantage of our global data-center and caching infrastructure, we can directly serve large numbers of user requests without having to query other DNS resolvers.
Help make the web faster and more secure. We are launching this experimental service to test some new ways to approach DNS-related challenges. We hope to share what we learn with developers of DNS resolvers and the broader web community and get their feedback.

Google Public DNS: what it is and isn’t

Google Public DNS is a recursive DNS resolver, similar to other publicly available services. We think it provides many benefits, including improved security, fast performance, and more valid results. See below for an overview of the technical enhancements we’ve implemented.

Google Public DNS is not, however, any of the following:

A top-level domain (TLD) name service. Google is not an operator of top-level domain servers (generic or country-code), such as Verisign.
A DNS hosting or failover service. Google Public DNS is not a third-party DNS application service provider, such as DynDNS, that hosts authoritative records for other domains.
An authoritative name service. Google Public DNS servers are not authoritative for any domain. Google maintains a set of other nameservers that are authoritative for domains it has registered, hosted at ns[1-4].google.com.
A malware-blocking service. Google Public DNS does not perform blocking or filtering of any kind.

Changing your DNS servers settings

Microsoft Windows

DNS settings are specified in the TCP/IP Properties window for the selected network connection.

Example: Changing DNS server settings on Microsoft Windows Vista

Go the Control Panel.
Click Network and Internet, then Network and Sharing Center, then Manage network connections.
Select the connection for which you want to configure Google Public DNS. For example:
- To change the settings for an Ethernet connection, right-click Local Area Connection, and click Properties.
- To change the settings for a wireless connection, right-click Wireless Network Connection, and click Properties.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Select the Networking tab. Under This connection uses the following items, click Internet Protocol Version 4 (TCP/IPv4), and then click Properties.
Click Advanced and select the DNS tab. If there are any DNS server IP addresses listed there, write them down for future reference, and remove them from this window.
Click OK.
Select Use the following DNS server addresses. If there are any IP addresses listed in the Preferred DNS server or Alternate DNS server, write them down for future reference.
Replace those addresses with the IP addresses of the Google DNS servers: 8.8.8.8 and 8.8.4.4.
Restart the connection you selected in step 3.
Test that your setup is working correctly; see Testing your new settings below.
Repeat the procedure for additional network connections you want to change.

Mac OS X

DNS settings are specified in the Network window.

Example: Changing DNS server settings on Mac OS 10.5

From the Apple menu, click System Preferences, then click Network. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Select the connection for which you want to configure Google Public DNS. For example:
- To change the settings for an Ethernet connection, select Built-In Ethernet, and click Advanced.
- To change the settings for a wireless connection, select Airport, and click Advanced.
Select the DNS tab.
Click + to replace any listed addresses with, or add, the Google IP addresses at the top of the list: 8.8.8.8 and 8.8.4.4.
Click Apply and OK.
Test that your setup is working correctly; see Testing your new settings below.
Repeat the procedure for additional network connections you want to change.

Linux

In most modern Linux distributions, DNS settings are configured through Network Manager.

Example: Changing DNS server settings on Ubuntu

In the System menu, click Preferences, then click Network Connections.
Select the connection for which you want to configure Google Public DNS. For example:
- To change the settings for an Ethernet connection, select the Wired tab, then select your network interface in the list. It is usually called eth0.
- To change the settings for a wireless connection, select the Wireless tab, then select the appropriate wireless network.
Click Edit, and in the window that appears, select the IPv4 Settings tab.
If the selected method is Automatic (DHCP), open the dropdown and select Automatic (DHCP) addresses only instead. If the method is set to something else, do not change it.
In the DNS servers field, enter the Google Public DNS IP addresses, separated by a space: 8.8.8.8 8.8.4.4
Click Apply to save the change. If you are prompted for a password or confirmation, type the password or provide confirmation.
Test that your setup is working correctly; see Testing your new settings below.
Repeat the procedure for additional network connections you want to change.

Google code site for DNS offering (Source of above information).

Breakdown by: TKJunkMail
From DSLreports Forum.