A simple question, please help

Kevin Darcy kcd at chrysler.com
Mon Jul 20 18:01:52 UTC 2009


Ken Lai wrote:
> Scott Haneda wrote:
>> 99% of the time openDNS works by just pointing some agent to their ip 
>> space.
>>
>> That 1% of the time, openDNS tries to make DNS responses that are 
>> modified in a way to try to help you.
>>
>> Maybe this is your issue?
>>
>> Googl.com being common enough they elect to return the google.com's 
>> answer istead.
>>
>> By default openDNS does not know how to return NXDOMAIN.
>>
>> This is fine for end users. This is bad for developed and servers.
>>
>> OpenDNS also does phishing URL blocking, stats, and a lot more.
>>
>> If you plan on using them as a resolver you want to be accurate, you 
>> must disable these features. Simply create an account with open DNS, 
>> login, add your IP, and disable all respond modification settings.
>>
>> Make sure someone elses IP has not been inherited by you with 
>> settings you will not want.
>>
>> I used to reccomend openDNS to everone. I found a problem in their 
>> system many many months back. Despite a small effort to resolve it, 
>> they have seemingly forgot about the problem.
>>
>> Maybe someone else here has recommendationd to huge robust recursive 
>> resolvers that do not focus on any response modification.
>>
> thanks for your replays.
>
> but the forwarders in the zone entry seems not work for me, which has 
> mentioned in the manual.
>
> the opendns return a A: 119.167.247.147
>
> but the other return 121.199.253.147, which i want to use
>
> if i remove the forwarders in option, the answer is right.
Well, you haven't told us the name you're looking up, so troubleshooting 
is going to be limited to mainly speculation.

I tried doing reverse lookups on both of those addresses, but it gave me 
no insight into what you're actually trying to look up as a forward name.

Note that if you want named to use forwarders *exclusively* then you 
should specify "forward only" along with each forwarders definition. 
Otherwise, if the forwarders are unavailable, even if only temporarily, 
named may fall back to using iterative resolution, i.e. following the 
delegation hierarchy to get the answer, all of the way down from the 
root zone, if necessary. This may give inconsistent answers and, if 
you're relying on seeing the "cooked" responses from OpenDNS, 
potentially undesirable lookup results.

- Kevin




More information about the bind-users mailing list