Topic: Faster DNS

[mistere]

I just downloaded and executed from my workstation a DNS test program, namebench (http://code.google.com/p/namebench/)

It tells me that my fastest DNS is Verizon NSRest US and that the mean response is 334% faster than my SME server.  To be fair, the six fastest responses were from the SME server but they were all for sites that I had visited in the last week or two.  7 of the 12 slowest were the SME server.  Ouch!  The fastest of the 7 slowpoke responses (333 ms)  was 50% slower than the slowest VerizonNSRestUS DNS resolution (227 ms)  Double ouch!

How can I direct the SME server's DNS to use VerizonNSRestUS for it's primary DNS lookup?  I presume that would make the SME DNS server nearly as fast as the VerizonNSRestUS DNS?

Does the namebench test methodology seem reasonable?  They offer detailed results in a CSV form.

TIA,
Eric

[mmccarn]

From server-manager, select 'Domains' (under 'Configuration'), then set the DNS server you want to use (the fast Verizon server) under 'modify Corporate DNS settings'.

Be aware that if Verizon decommissions the specific DNS server you decide to use your SME will lose all DNS.  I've had 3 Verizon customers experience this problem since 1995 (Verizon DNS IP set up in the router, DNS stops working -- call Verizon, get told "that server doesn't work any more; you need to use this other server...).

[mistere]

Thanks for the info.

I executed 3 more namebench runs and got different results each time.  Interestingly, the Verizon DNS did not appear in any of those results!  Google-public-dns-b was tops for one run and was listed as "slower replica of google-public-dns-a" for the other two runs.

I believe I've now totally confused myself and I'm just going to leave the DNS settings alone.

[janet]

mistere

The DNS server built in to sme talks to top level root DNS servers, so speed wise you should have nothing to worry about when using sme defaults (ie don't specify a DNS server).
See http://wiki.contribs.org/SME_Server:Documentation:Administration_Manual:Appendix

[mistere]

I read that and I agree, in principle, that the SME server should be plenty fast enough.
In reality, in every test I ran the SME server has the slowest mean response time of the 10 DNS servers.  Usually the response time was nearly three times longer that of the quickest server.  The problem is the benchmark never identified a single DNS server that was better - the list constantly changed.

I've given up on the idea of changing this because it's clear to me that identifying the single DNS server that is the "best" will take more time that I will ever save by using this ephemeral better DNS.

Thanks.