Some ISP’s highjack domain queries with typos to earn additional revenue from the user. Others might block website access with the help of the DNS system.

Public DNS servers can be an alternative. Common ones are Open DNS, Google DNS or Norton DNS among others.

They often offer features that the ISP dns servers are not offering. This may including blocking of advertisement or tracking related scripts, or parental controls to protect minors from Internet threats.

Experienced computer users should not have issues changing DNS servers on their computer. Inexperienced users on the other hand might prefer to use a tool that automates the process.

Public DNS Server Tool is a free portable program for Windows that can change the DNS server of installed network cards. It is similar to DNS Jumper which can also be used for the purpose.

It takes two clicks after program start to change the DNS server. You need to select a network card first if multiple cards are installed on the system. You can ignore the network interface card pulldown menu otherwise.

A click on the public dns servers menu displays the list of supported services. This includes Google DNS, Open DNS, Norton DNS, Comodo Secure, ScrubIt DNS and DNS Advantage. Just select one of the providers from the list and click on change afterwards to use the new DNS server from that moment on on the system.

You can alternatively change the IPs directly in the current DNS servers listing.

The program is not displaying information about the providers, which may make it necessary to do some digging of your own. You may also like to use the DNS Server benchmark tool to test the connection speed.

Windows users can download the Public DNS Server Tool from the developer website. The program is compatible with 32-bit and 64-bit editions of the operating system.

Not every DNS server is equal on the other hand, and it is not only a performance question either. Performance on the other hand plays a big role and it is quite possible to speed up the connections on the Internet by switching to a better performing DNS server.

Besides speed, it can also benefit the freedom of speed and other functionality. Internet Service Provider, the state or organizations make use of the DNS system to block access to websites and services on the Internet. It is not a foolproof protection but it has the effect that the DNS server resolves to a different IP, or none at all so that the website cannot be accessed by entering its domain name in the browser. That can be easily bypassed with anonymous proxies, virtual private networks, entering the IP directly or switching the DNS server.

Some DNS providers add filters and blocklists to their services as well, for instance to block known malicious websites automatically in order to protect their users. Open DNS does that for instance.

DNS Performance Test is a free tool for Windows, Macintosh and Linux that queries a random set of 10,000 urls to determine a DNS server’s mean query time. The list is generated randomly on startup, the only available option for the user is to start the performance test.

The DNS test takes time to complete which should be clear as each connection can take anywhere between 10 and a few thousand milliseconds.

Statistics are displayed on the Stats tab. They can be accessed even while the performance test is still running. It shows the best, worst and average query time, the number of successful queries, the timeouts and gives an assessment of the overall DNS server performance.

If the DNS server performance is bad it may make sense to try another DNS server provider to see if the situation changes. This would mean that the DNS performance test needs to be run again before the results can be compared.

DNS Performance Test is available for download at the developer website.

Manually changing a network adapter’s IP address, and other network related information may be an option if done irregularly, but a software to automate most of the process could save a lot of time.

TCP Profiles Manager is a basic software for this purpose. It supports the creation of multiple network profiles, but limits the parameters that may be changed to TCP/IP and DNS settings.

tcp profiles manager

The program on startup displays a list of available profiles, and options to create, delete, edit and activate profiles in the left sidebar. First time users should make sure that English is the selected language of the program. As a side note, the installation is only available in French, the software itself in English and French.

A new network profile requires the selection of a name, icon, network interface, either manual or automatic IP address settings, and a manual or automatic selection of DNS servers.

internet protocol

TCP Profiles Manager lacks some of the features that previously reviewed applications offer. Network Settings Manager for instance offers options to configure default printers, network drives, WINS or scripts for each network profile.

Even the similar Network Profile Switcher supports plugins to change settings like the Internet Explorer proxy automatically for each network profile.

Still, Windows users who are looking for a program that changes IP and DNS related network settings automatically, may take a look at TCP Profiles Switcher. Advanced users, and users who require more functionality may be better of with NetSetMan.

TCP Profiles Manager is compatible with 32-bit and 64-bit editions of the Windows operating system. It has been tested on a Windows 7 Pro 64-bit system.

The web filter is fully customizable to block only the selected contents in the network the DNS servers are used. Those filtering customizations are on the other hand only available for free or paid OpenDNS account owners and not for users who have simply switched their DNS servers to the provider.

OpenDNS FamilyShield has been designed for families who want a ready to run solution. The DNS servers come with family friendly filtering activated so that account creation and configuration is not necessary.

Filters to block adult contents, proxies and anonymizers are automatically active after changing the DNS servers to the FamilyShield IPs.

DNS servers have an advantage over parental control software as they can be configured on a computer system or router. All devices that use the router to connect to the Internet are benefiting from the web filtering and additional security. Parental control software on the other hand can only be installed on supported computer systems and not devices such as Microsoft’s Xbox 360, Sony’s Playstation 3, Nintendo’s Wii or 3Ds as they are usually operating system specific.

The DNS server IPs that need to be used are 208.67.222.123 and 208.67.220.123. These need to be entered into the router configuration or computer configuration, depending largely on the network setup and situation.

opendns familyshield

The OpenDNS Knowledge Base contains information on how to setup the DNS servers on various operating systems and devices.

Advanced users might prefer the manual approach by creating an account to block only specific web contents. Families on the other hand can use the DNS servers to install a solid web filtering solution without the hassles of configuration.

The best way to find out is to test Google’s public DNS servers to see if they offer any speed improvements. We covered a DNS benchmark tool called Namebench a while ago which can be used for that purpose.

But the benchmark software might not be needed in some cases. Some users would probably like to test the DNS servers by simply switching to them in their operating system to see if they notice any speed improvements.

Google DNS Helper has been designed for this user group. The portable program provides one click access to switch the computer’s current DNS server to Google’s public server.

Even better is the restore DNS option to restore the previous DNS server if Google’s DNS server did not live up to the promises made.

Google DNS Helper is a portable software program for the Windows operating system. The 89 Kilobyte program can be downloaded from the developer’s website. It requires the Microsoft .net Framework to run.

While it is not difficulty to change the DNS servers in the operating system it does require some knowledge as to where they are changed. And the IP addresses of the DNS server need to be known as well to apply the changes to the computer system.

DNS Jumper is a free and portable software program that aids the user by providing a one-click system to change DNS servers in Windows. The application displays a list of DNS servers that can be activated with the click of the mouse button. Available DNS server range from Google DNS over Open DNS to Ultra DNS, Level 3, Open NIC to the default DNS server of the system.

Changing DNS servers is therefor a breeze with DNS Jumper. The program does on the other hand lack relevant information and a configuration to edit the available DNS servers. DNS Jumper can be downloaded from the the Fiber Download website (via ASK VG)

Namebench is a free and portable software program for Microsoft Windows, Linux and Apple Macintosh computers that can perform these DNS benchmarks for the user. The program will automatically discover the DNS servers that are currently used by the connections and add those to a list of available public DNS servers. The computer user has furthermore the chance to add further DNS servers to the benchmark.

Namebench will then take website samples from a web browser’s history file. It will by default pick the web browser with the largest history giving the user the choice to switch to another web browser in the benchmark preparations. The number of tests and the number of runs can be configured in the interface as well.

The test can take some time which largely depends on the number of runs and tests but also on the number of DNS servers that have been added by the user to the program. Namebench will then calculate the best nameservers and generate a local webpage with the test results.

The performance increase (or decrease) along with the nameservers that need to be configured for it are displayed on top of the report.

A detailed report follows that displays the test results of the tested DNS servers. This includes their IP, average, minimum and maximum response time, errors, no answers and notes.

Various graphs are displayed in the end that display the response times of the tested DNS servers.

Namebench can be downloaded from it’s Google Code project page. (via Download Squad)

The Internet Service Provider is usually the one that is providing the DNS servers to the customer. This happens more often than not automatically. There are however reasons to switch to other DNS servers with performance, privacy and censorship being three of the major reasons.

Censorship: Some countries use DNS to block access to websites. This is a weak block that can easily be bypassed by the user by entering the IP address of the website instead of its domain name.

Privacy: Many ISPs cash in on domain typing errors by displaying a custom error page to the user instead of the simple “page not found” error page.

Performance: Some ISPs offer DNS servers that are not optimized, slow and sometimes even unreachable.

Users who experience some of these difficulties can switch DNS servers. One of the most prominent free DNS providers was Open DNS which not only offers a fast independent DNS system but also additional optional values that include phishing and web content filters.

Google today announced that they have started offering public DNS servers as well. The system, called Google Public DNS, was designed to “make users’ web-surfing experiences faster, safer and more reliable”.

Speed: Resolver-side cache misses are one of the primary contributors to sluggish DNS responses. Clever caching techniques can help increase the speed of these responses. Google Public DNS implements prefetching: before the TTL on a record expires, we refresh the record continuously, asychronously and independently of user requests for a large number of popular domains. This allows Google Public DNS to serve many DNS requests in the round trip time it takes a packet to travel to our servers and back.

Security: DNS is vulnerable to spoofing attacks that can poison the cache of a nameserver and can route all its users to a malicious website. Until new protocols like DNSSEC get widely adopted, resolvers need to take additional measures to keep their caches secure. Google Public DNS makes it more difficult for attackers to spoof valid responses by randomizing the case of query names and including additional data in its DNS messages.

Validity: Google Public DNS complies with the DNS standards and gives the user the exact response his or her computer expects without performing any blocking, filtering, or redirection that may hamper a user’s browsing experience.

A Google Code page details how to change the DNS servers to use Google Public DNS servers. Experienced users need to use the following two DNS servers.

8.8.8.8
8.8.4.4

Privacy Concerns

But what about Privacy? Users who use the Google Public DNS servers will automatically submit extensive data to Google that includes all the websites and other services on the Internet that they visit.

According to the privacy information posted on the project web page Google Public DNS records temporary and permanent data but does not “correlate or combine” these information “with any other log data that Google might have about your use of other services, such as data from Web Search and data from advertising on the Google content network”.

Temporary Logs: The temporary logs store the full IP address of the machine you’re using. We have to do this so that we can spot potentially bad things like DDoS attacks and so we can fix problems, such as particular domains not showing up for specific users. We delete these temporary logs within 24 to 48 hours.

Permanent Logs: In the permanent logs, we don’t keep personally identifiable information or IP information. We do keep some location information (at the city/metro level) so that we can conduct debugging, analyze abuse phenomena and improve the Google Public DNS prefetching feature. After keeping this data for two weeks, we randomly sample a small subset for permanent storage.

Verdict:

Some users will say that providing public DNS servers is just another step in Google’s world domination plans. Others might find out that the benefits outweigh the doubts and concerns. It is definitely not bad to have another option in this field especially with the increasing censorship around the world.

This can be problematic for webmasters who face the same DNS propagation wait time especially if they want to make sure that the website works fine at the new hosting location. There is one easy way of accessing the website at the new web server even if the DNS is still pointing to the old: The Hosts file.

The Hosts file can be used to map a domain name to an IP address. All that needs to be done to work with a website before DNS propagation is to map the domain name to the new IP address. Here is how this is done in the Windows operating system.

The Hosts file in Windows is located at C:\Windows\System32\drivers\etc\Hosts

You might need to change the rights of the current logged in user first so that the file becomes writable.

All you should see when opening the Hosts file with a text editor is a comment section on top unless someone else has already added new entries to it.

New entries to the Hosts file can be added after the last line. To do that add the IP address of the new server and then the domain name of the website like 96.30.22.116 acerliquid.net with a blank in between. All programs of the operating system will now open the website using the new IP address even if the DNS servers are still routing to the old server. This gives webmasters an excellent opportunity to edit these websites before the DNS propagation has finished.

Whenever you try to access a website you type its url into the address bar. The url is then send to the DNS server who looks up the IP for that website and sends it back to your browser to be able to make the connection to the website. To censor one would simply return no IP or a different IP that redirects to another website. (something like, no no, this is no website that you should visit, bla bla)

This means that the website that you want to access exists of course but the information on the dns server was changed to prevent access. There are two options that let you access the website. The first would be to simply enter the IP address of the website that you want to visit instead of the url. You can use scripts that are freely available on the internet to lookup the IP of an url.

This method is only working if there is only one url that is using that IP. You are out of luck if many websites are hosted on the same server. The second method which is reliable and working for all occasions helps us in this case.

If you change the DNS server that your computer is using to lookup the IP you will receive the correct result. Let us say that you life in China and that China banned access to Wikipedia. Instead of using a Chinese DNS server you use one from the United States which has the information that you need to access Wikipedia.

OpenDNS, a free service, would be one alternative as would be the following list which I have taken from freerk.com

• dns2.de.net – 194.246.96.49 (Frankfurt, Germany)
• ns1.de.eu.orsn.net – 217.146.139.5 (Hildesheim, Germany)
• resolver.netteam.de – 193.155.207.61 (Alfter-Impekoven, Germany)
• sunic.sunet.se – 192.36.125.2 (Stockholm, Sweden)
• master.ns.dns.be – 193.109.126.140 (Leuven, Belgium)
• ns1.lu.eu.orsn.net – 195.206.104.98 (Belvaux, Luxembourg)
• merapi.switch.ch – 130.59.211.10 (Zurich, Switzerland)
• prades.cesca.es – 192.94.163.152 (Barcelona, Spain)
• michael.vatican.va – 212.77.0.2 (Vatican City, Italy)
• dns.inria.fr – 193.51.208.13 (Nice, France)
• ns0.ja.net – 128.86.1.20 (London, UK)
• nic.aix.gr – 195.130.89.210 (Athens, Greece)
• ns.ati.tn – 193.95.66.10 (Tunis, Tunisia)
• ns1.relcom.ru – 193.125.152.3 (Moscow, Russia)
• trantor.umd.edu – 128.8.10.14 (College Park, MD, USA)
• ns1.berkeley.edu – 128.32.136.9 (Berkeley, CA, USA)
• merle.cira.ca – 64.26.149.98 (Ottawa, Canada)
• ns2.dns.br – 200.19.119.99 (Sao Paulo, Brasil)
• ns2.gisc.cl – 200.10.237.14 (Santiago, Chile)
• ns.uvg.edu.gt – 168.234.68.2 (Guatemala, Guatemala)
• ns1.retina.ar – 200.10.202.3 (Buenos Aires, Argentina)
• ns.unam.mx – 132.248.253.1 (Mexico City, Mexico)
• ns.wide.ad.jp – 203.178.136.63 (Osaka, Japan)
• ns.twnic.net – 192.83.166.11 (Taipei, Taiwan)
• ns3.dns.net.nz – 203.97.8.250 (Wellington, New Zealand)
• box2.aunic.net – 203.202.150.20 (Melbourne, Australia)

Changing the DNS Server is a matter of minutes. It depends on the operating system that you are using. In Windows XP you open the control panel and click on network connections. You right-click your connection and select Properties from the context menu.

Select the Internet Protocol (TCP / IP) and click on Properties in that menu. Click on use the following DNS server addresses and enter a preferred and alternate DNS server into the fields. Make sure you enter the IPs. Apply and close the menu and restart your computer. Once that is done you are using the new DNS server which should bypass the censorship.