DNS Benchmark Conclusions & Recommendations

What the results you have just obtained mean to YOU

The results summary, conclusions, and recommendations from your most recent run of this DNS benchmark are provided below. Please carefully consider the implications of making any changes to your system's current configuration before doing so.


ý Only the built-in default resolvers were benchmarked.
Please consider taking the time to create a custom resolver list.
This is a reminder about the tremendous benefits to be gained from benchmarking the "Top 50" resolvers that are found for you by the Benchmark's custom resolver list builder. When you have time, don't forget to give that a try. The results will astound you! You can find the option to do this on either the application's System Menu (Alt-Spacebar) or on the Add/Remove nameservers dialog on the Nameservers page.


þ System has multiple redundant nameservers configured.
This system is currently configured to use 6 separate nameservers for DNS name resolution. This is in keeping with recommended best practice (of having at least two different nameservers) so that the temporary failure of any single nameserver will not prevent all DNS name resolution.


þ All system nameservers are alive & replying to queries.
All of this system's 6 nameservers are working and replying to queries. This is terrific because if the system's primary nameserver were to become overloaded or unavailable, even briefly, one or more backup nameservers are standing by ready to supply DNS lookup services.


ý System nameservers are NOT ordered for best performance!
Windows uses DNS servers in the order they are listed under the network adapter's properties, or when obtained automatically from an ISP, in the order provided by the ISP. Windows will fall back to using the second, third, and other nameservers only when the first listed nameserver fails to respond. So if the first nameserver happened to be very slow, but working, everything would be slowed down. Consequently, the order of nameserver listing should match their order of decreasing performance . . . but this is not how this system is currently configured:

In this most recent test, a faster nameserver
was listed in order after a slower one.

The following table shows the order of this system's usage of its configured nameservers versus their comparative performance ranking:

     Usage Order   Nameserver IP   Speed Rank
     -----------  ---------------  ----------
           1       81. 17.184.  1      6
           2       62. 77.196.  1      5
           3        8.  8.  8.  8      4
           4        8.  8.  4.  4      1
           5       85. 67.159. 35      3 unreliable
           6       85. 66. 85.120      2 unreliable

With at least 95% Certainty. . .
You have received this "red flagged" message because there was enough of a statistically significant difference between the benchmarked nameserver performance for this program to make a highly confident determination that improvement is possible by "re-ordering" this system's nameservers.

Recommended Actions:

Before you make any changes:  Even though there appears to be a statistically significant difference in the measured performance of these nameservers, you should re-run the benchmark - perhaps at different times of the day, and even on different days - to verify that the current configuration consistently produces this "misordering" note (the slower nameserver might just be having a bad day.)  If the trouble persists, then changing the nameserver order will definitely improve your system's Internet performance!


þ System nameservers are faster than ALL public alternatives.
All of the DNS resolvers your system is using are responding faster than any of the 100% reliable publicly available alternative DNS nameservers this benchmark utility just tested. Therefore, there would be no performance benefit from replacing any of this system's current nameservers with any of those publicly available alternatives. However, this best performance appraisal assumes that this system's nameservers are 100% reliable. See the next item below for an appraisal of your nameservers' reliability.

Note: If there appeared to be one or more faster public alternative nameservers, there was enough uncertainty created by the spread of benchmark timing results that it was not possible to be at least 95% confident that any of those faster-seeming nameservers really were reliably faster than the nameservers this system is currently using. So it made no sense to alarm you about the need to change things when there was insufficient evidence.


ý One or more system nameservers is NOT 100% reliable!
DNS reliability is extremely important, since lookup requests that are dropped and ignored by nameservers cause significant delays in Internet access while the querying system waits for a reply. The system is then finally forced to reissue the query to the same or to backup nameservers. While your system is patiently waiting for a reply, you are impatiently waiting to get on with your Internet access.

During this benchmark test, the nameservers being tested did not reply to some of the DNS queries they were sent.

So the question now is: Did the benchmark discover alternative nameservers having superior performance and reliability to which you could switch in order to obtain more performance and reliability?

Important Note:

Incorrect warnings of low reliability nameservers can arise if (1) DNS benchmarking is being performed while the local network is busy performing other work such as file downloading, or (2) the benchmark is running over a wireless (WiFi) link with low signal strength or high interference. Please try to minimize any other local network activity while the benchmark is running, and use a wired (not wireless) LAN connection if possible.

Recommended Actions:

Before you make any changes, you should probably run the benchmark a few more times at differing times of day to make sure that the troubling reliability is an ongoing problem and not just a brief occurrence.

You may also wish to consult the "Tabular Data" page which summarizes all benchmark results in numeric tables. The numbers make it easier to see exactly how unreliable your system's nameservers are compared with the available alternatives. (And also how the alternatives' performance compares.)


þ All of this system nameservers return errors.
This is a GOOD thing!  Some DNS providers, such as OpenDNS and even the Earthlink, Roadrunner and Comcast ISPs, redirect incorrectly entered URLs to their own advertising-laden marketing-driven interception page instead of simply returning an error to the web browser. But this system's nameservers are returning errors when asked to lookup non-existent domain names.


þ System nameservers are replying to all query types.
During the development of this DNS Benchmark we discovered that the routers used by some pre-release testers were not returning results for the benchmark's Uncached and/or Dotcom testing queries. Even though these queries are admittedly unusual, they are completely valid. So the only conclusion was that those few routers were inherently defective. The good news here is that your nameservers are replying to these unusual but valid queries.


____________________________________________________________________

REMEMBER TO CHECK SPOOFABILITY !!
Whether you make any changes to your nameservers or not, but
especially if you do, be sure to verify the security of your final DNS
resolver set by using GRC's free "DNS Spoofability" testing service!

 http://www.GRC.com/dns/dns.htm
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If you require assistance . . .

If you require assistance with the implementation any of the suggested changes to your system's DNS configuration, several sources of help are available:

For help with the operation and use of this DNS Benchmark program, please reference the extensive DNS Benchmark pages at the GRC website:

 http://www.GRC.com/dns/benchmark.htm

For help with any of the specific conclusions or recommendations above, please see the DNS Benchmark FAQ (Frequently Asked Questions) page:

 http://www.GRC.com/dns/benchmark-faq.htm

Knowledge of the DNS domain name system is widespread among those in public technical Internet forums. You will very likely be able to obtain answers to any specific questions you may have by asking knowledgeable inhabitants of online communities.

GRC maintains and operates a comprehensive online "newsgroup" community and has a specific newsgroup - grc.dns - dedicated to the discussion of DNS issues including this DNS benchmark program (where it was developed) and GRC's online DNS Spoofability testing service. Please see the following web page for help with joining and participating in GRC's terrific newsgroups:

 http://www.GRC.com/discussions.htm

GRC's technical support services are limited to the support of licensees of our commercial software products and do not extend to the support of our freely available software or online services. Please do not write to us (GRC / Gibson Research Corporation) for assistance in connection with this freeware utility.

You will find that ample help is freely available
within the Internet community.  Thank you!

- Steve Gibson

Please Note: This program is Copyright (c) 2010 by Gibson Research Corporation -- ALL RIGHTS RESERVED. This program is FREEWARE. Although it may not be altered in any way, it MAY BE FREELY COPIED AND DISTRIBUTED onto and through any and all computer media in ANY form or fashion. You are hereby granted the right to do so.
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