Open Resolver Problems

Tue Mar 26 17:33:43 UTC 2013

On 3/26/13 10:10 AM, Owen DeLong wrote:
> On Mar 26, 2013, at 9:39 AM, Doug Barton <dougb at dougbarton.us> wrote:
>
>> On 03/26/2013 09:28 AM, Owen DeLong wrote:
>>> On Mar 26, 2013, at 5:59 AM, Chris Adams <cmadams at hiwaay.net> wrote:
>>>
>>>> Once upon a time, Valdis.Kletnieks at vt.edu <Valdis.Kletnieks at vt.edu> said:
>>>>> Now explain how you find a recursive nameserver that isn't listed in an NS
>>>>> entry and *hasn't* been publicized someplace that Google can find it.
>>>> The same way you find open mail relays, SSH hosts with weak
>>>> user/password combos, bad WordPress installs, etc. - scan for them.  If
>>>> it is open to the Internet, it will be found (or probably already has
>>>> been).
>>>>
>>> Let me rephrase the question… How do you find an open IPv6 recursive name server
>>> that isn't listed in an NS entry and hasn't been publicized someplace that Google can
>>> find it?
>> That question was already answered ... ask the bots what their resolving name servers are, then check to see if they are open. As IPv6 deployment increases, the answers will increasingly include IPv6 open resolvers.
>>
>> Doug
>>
> Let me again rephrase…
>
> As a white-hat attempting to find problems to address through legitimate means, how
> do you …
passive DNS collection , e.g. many people lave large lists of resolvers 
that have connected to their authoritative nameservers.
>
> Owen
>
>
>