My window to the world


Why bother with Google DNS (or any other third party DNS resolver)?

By Mauricio Freitas, in , posted: 5-Dec-2009 18:07

The web is hot with news of a new, free DNS resolver service powered by Google. A DNS resolver will answer requests from your computer or router and translate names (such as www.geekzone.co.nz) into IP addresses such as 210.48.73.74 - the actual address servers are known by on the Internet.

This is not the first third party DNS resolver server around - other well known services include OpenDNS and DynDNS Internet Guide. These services already offer more feature than Google's free resolver - including automatic blocking of known malware sites, adult sites, custom configuration based on account and your network.

Most users will probably be interested in getting quicker replies to their DNS requests - after all a webpage may contain many invidual items and each will require access to a server, so ultimately just loading a single webpage may require many DNS requests. Obviously this applies to first visits to a domain - most OS or routers will cache DNS responses locally.

But are these third party DNS resolvers faster? I used the DNS Benchmark program to test my ISP's own DNS resolver (TelstraClear), an alternative TelstraClear DNS resolver (old Paradise servers), Telecom DNS resolver, WorldxChange DNS resolver, OpenDNS, DynDNS and Google DNS.

The results, from a New Zealand perspective, are below. As you can see Google DNS is certainly not the fastest of the bunch. Actually both Google DNS resolvers are slower than everything else, except for one of the DynDNS servers (the other DynDNS server is actually faster than Google's).

Another important thing to consider when using a third party DNS is how well your ISP work with services that use a CDN (Content Distribution Network). A CDN uses geographically distributed servers to bring content closer to users. This means when you access content from microsoft.com you might be accessing a server in Singapore, while people in London will access the same content from a server in Europe.

For this to work the DNS resolver will give your computer the DNS to the closest location. When you use a third party DNS resolver, one sitting in the U.S. for example, you will get the wrong "closest" location. On TelstraClear for example this will cause problems with their stateful firewall. Your computer will request some elements from Facebook for example targeting a server in the U.S. but the response comes from a server in Singapore. At this moment their firewall will block the connection - and your browser will be there waiting forever (or for a very long time).

So it's not always great to use a third party DNS resolver - unless you know exactly why and how.

image

  Final benchmark results, sorted by nameserver performance:
(average cached name retrieval speed, fastest to slowest)

  203. 96.152. 12 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.010 | 0.012 | 0.020 | 0.002 | 100.0 |
  - Uncached Name | 0.154 | 0.198 | 0.325 | 0.043 | 100.0 |
  - DotCom Lookup | 0.156 | 0.226 | 0.334 | 0.062 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                 kirsty.paradise.net.nz
                    TelstraClear Ltd

  203. 96.152.  4 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.010 | 0.013 | 0.017 | 0.002 | 100.0 |
  - Uncached Name | 0.151 | 0.197 | 0.328 | 0.042 | 100.0 |
  - DotCom Lookup | 0.151 | 0.261 | 0.338 | 0.066 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                 rachel.paradise.net.nz
                    TelstraClear Ltd

   58. 28.  6.  2 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.019 | 0.021 | 0.025 | 0.001 | 100.0 |
  - Uncached Name | 0.019 | 0.021 | 0.026 | 0.001 | 100.0 |
  - DotCom Lookup | 0.019 | 0.022 | 0.027 | 0.002 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                      ns2.wxnz.net
               WorldxChange Communications

  203. 97. 78. 43 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  + Cached Name   | 0.019 | 0.021 | 0.025 | 0.001 | 100.0 |
  + Uncached Name | 0.147 | 0.188 | 0.302 | 0.032 | 100.0 |
  + DotCom Lookup | 0.150 | 0.257 | 0.332 | 0.069 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                  ns1.acld.clix.net.nz
                    TelstraClear Ltd

  203. 97. 78. 44 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  + Cached Name   | 0.019 | 0.022 | 0.028 | 0.002 | 100.0 |
  + Uncached Name | 0.148 | 0.191 | 0.319 | 0.040 | 100.0 |
  + DotCom Lookup | 0.148 | 0.230 | 0.338 | 0.061 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                  ns2.acld.clix.net.nz
                    TelstraClear Ltd

  202. 27.158. 40 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.019 | 0.022 | 0.028 | 0.002 | 100.0 |
  - Uncached Name | 0.153 | 0.209 | 0.332 | 0.046 | 100.0 |
  - DotCom Lookup | 0.147 | 0.168 | 0.208 | 0.019 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                    dnsc1.xtra.co.nz
                    Telecom Xtra ISP.

  202. 27.156. 72 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.018 | 0.026 | 0.186 | 0.024 | 100.0 |
  - Uncached Name | 0.150 | 0.209 | 0.327 | 0.045 | 100.0 |
  - DotCom Lookup | 0.146 | 0.172 | 0.209 | 0.021 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                    dnsc2.xtra.co.nz
                    Telecom Xtra ISP.

  216.146. 35. 35 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.146 | 0.149 | 0.154 | 0.002 | 100.0 |
  - Uncached Name | 0.150 | 0.210 | 0.322 | 0.056 | 100.0 |
  - DotCom Lookup | 0.151 | 0.225 | 0.312 | 0.055 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
            resolver1.dyndnsinternetguide.com
                Dynamic Network Services

  208. 67.222.222 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.146 | 0.149 | 0.157 | 0.002 | 100.0 |
  - Uncached Name | 0.148 | 0.212 | 0.345 | 0.057 | 100.0 |
  - DotCom Lookup | 0.150 | 0.267 | 0.336 | 0.056 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                  resolver1.opendns.com
                      OpenDNS, LLC

  208. 67.220.220 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.146 | 0.149 | 0.158 | 0.003 | 100.0 |
  - Uncached Name | 0.148 | 0.230 | 0.588 | 0.091 | 100.0 |
  - DotCom Lookup | 0.149 | 0.248 | 0.321 | 0.060 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
                  resolver2.opendns.com
                      OpenDNS, LLC

    8.  8.  8.  8 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.177 | 0.192 | 0.477 | 0.046 | 100.0 |
  - Uncached Name | 0.181 | 0.245 | 0.485 | 0.074 | 100.0 |
  - DotCom Lookup | 0.192 | 0.297 | 0.386 | 0.066 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
             google-public-dns-a.google.com
                 Level 3 Communications

    8.  8.  4.  4 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.177 | 0.198 | 0.399 | 0.053 | 100.0 |
  - Uncached Name | 0.182 | 0.259 | 0.485 | 0.079 | 100.0 |
  - DotCom Lookup | 0.193 | 0.301 | 0.402 | 0.068 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
             google-public-dns-b.google.com
                 Level 3 Communications

  216.146. 36. 36 |  Min  |  Avg  |  Max  |Std.Dev|Reliab%|
  ----------------+-------+-------+-------+-------+-------+
  - Cached Name   | 0.212 | 0.214 | 0.219 | 0.002 | 100.0 |
  - Uncached Name | 0.214 | 0.282 | 0.492 | 0.062 | 100.0 |
  - DotCom Lookup | 0.231 | 0.277 | 0.335 | 0.034 | 100.0 |
  ----------------+-------+-------+-------+-------+-------+
            resolver2.dyndnsinternetguide.com
                Dynamic Network Services

   58. 28.  4.  2 | The DNS server at this IP address is
  actively refusing to answer queries made by this client.
  It should not be used for normal client-based resolution.
  ----------------+-------+-------+-------+-------+-------+
                      ns1.wxnz.net
               WorldxChange Communications

  UTC: 2009-12-05, from 04:51:33 to 04:52:26, for 00:52.613

Other related posts:
Microsoft Ignite New Zealand, Microsoft Surface Studio
Geekzone data analytics with Power BI
Now with more fibre






comments powered by Disqus

freitasm's profile

Mauricio Freitas
Wellington
New Zealand


I live in New Zealand and my interests include mobile devices, good books, movies and food of course! 

I'm the Geekzone admin. On Geekzone we publish news, reviews and articles on technology topics. The site also has some busy forums.

Subscribe now to my blog RSS feed or the Geekzone RSS feed.

If you want to contact me, please use this page or email me freitasm@geekzone.co.nz. Note this email is not for technical support. I don't give technical support. You can use our Geekzone Forums for community discussions on technical issues.

Here's is my full disclosure post.

A couple of blog posts you should read:

Social networks presence

View Mauricio Freitas's profile on LinkedIn


My Blog by tags...

Blog...
Entrepreneurship...
Media...
Personal...
State of Browsers...
Technology...
Viral Marketing...
Web Performance Optimization...
Windows...
Windows Phone...

Other recent posts in my blog

Microsoft Ignite New Zealand, ...
If the headlines indicate the ...
Geekzone data analytics with P...
State of browsers Geekzone Mar...
2Cheap Cars discussion...
Now with more fibre...
Unlimited is not unlimited: Vo...
How bad is Vodafone cable at t...
Frustrated with Microsoft Fami...
State of browsers Geekzone Mar...

New posts on Geekzone