dig +trace to find all the forwarders?

[Warren Kumari]

On Apr 26, 2010, at 4:00 PM, Lightner, Jeff wrote:

> I'm certainly behind a NAT and the IP reported is the NATed IP.

And is the recursive resolver that you are using ALSO behind the same  
NATed IP?!

>
> Maybe I missed the point in the site.   Is it to report the name  
> server
> your IP exist on (the one it returned the reverse lookup for) or is it
> intended to run only from a name server?  If the latter I don't see  
> the
> point of the site.

It is supposed to tell you the resolver that you are using -- actually  
what it tells you is the address of the resolver that queried their  
authoritative server. In the huge majority of the cases the resolver  
you are using == the address of the resolver that touched them. The  
original poster was asking if this was true for him (which is why I  
suggested that he tries this).

I reconfigured my home server to use the resolvers provided my my ISP  
(Verizon), and www.damia.com reports that my IP is: 71.114.43.183    
(which it is!)
and that the resolver I am using is: 71.252.0.36.


Anyway, this has wandered offtopic.
W


>
> -----Original Message-----
> From: Warren Kumari [mailto:warren at kumari.net]
> Sent: Monday, April 26, 2010 3:14 PM
> To: Lightner, Jeff
> Cc: Josh Kuo; bind-users at isc.org
> Subject: Re: dig +trace to find all the forwarders?
>
>
> On Apr 26, 2010, at 2:54 PM, Lightner, Jeff wrote:
>
>> I'm sure that's all it displayed when I went to it from my Windows
>> desktop's browser.
>
> Uuuummm....
>
> Are you maybe behind the same NAT that your recursive resolver is
> behind and so your IP == your resolvers IP? Or is your Windows desktop
> also your resolver?
>
> Can you check by just going to www.damia.com (or whatismyip.com or
> ipchicken.com or sshing into something and looking what your source is
> or  or or...)
>
> W
>
>
>>
>> -----Original Message-----
>> From: Warren Kumari [mailto:warren at kumari.net]
>> Sent: Monday, April 26, 2010 2:20 PM
>> To: Lightner, Jeff
>> Cc: Josh Kuo; bind-users at isc.org
>> Subject: Re: dig +trace to find all the forwarders?
>>
>>
>> On Apr 26, 2010, at 10:41 AM, Lightner, Jeff wrote:
>>
>>> ?
>>>
>>> That link only shows the IP you came from and does a reverse lookup
>>> on
>>> it.  It doesn't seem to say anything about the nameserver.
>>
>> Does it? Are you sure?
>>
>> If so, I sent the  wrong link -- the machine I was testing from is
>> also a nameserver, but I thought that was the right link...
>>
>> W
>>
>>>
>>> -----Original Message-----
>>> From: bind-users-bounces+jlightner=water.com at lists.isc.org
>>> [mailto:bind-users-bounces+jlightner=water.com at lists.isc.org] On
>>> Behalf
>>> Of Warren Kumari
>>> Sent: Monday, April 26, 2010 10:29 AM
>>> To: Josh Kuo
>>> Cc: bind-users at isc.org
>>> Subject: Re: dig +trace to find all the forwarders?
>>>
>>>
>>> On Apr 26, 2010, at 3:10 AM, Josh Kuo wrote:
>>>
>>>> What is happening is I suspect the DNS resolved IP given by my ISP
>>>> is
>>>> actually forwarding recursive queries to yet-another-server(s), and
>>>> is
>>>> introducing slow name resolution and timeouts.
>>>
>>> Well, if you are just trying to figure out if the nameserver you are
>>> asking is the one doing the resolution, this *might* help you out:
>>>
>>> http://www.damia.com/whatismydns/
>>>
>>> W
>>>
>>>
>>>> In any case, I will
>>>> have to involve the ISP in troubleshooting and (hopefully) fixing
>>>> the
>>>> problem. I was hoping there is some way to mimic "traceroute" with
>>>> "dig +trace", I didn't think so, and Mark confirmed it.
>>>>
>>>> On Sunday, April 25, 2010, Warren Kumari <warren at kumari.net> wrote:
>>>>>
>>>>> On Apr 25, 2010, at 12:01 AM, Josh Kuo wrote:
>>>>>
>>>>>
>>>>> You need administrative access to see the overides to the normal
>>>>> resolution
>>>>> process.
>>>>>
>>>>>
>>>>> Just so I understand this completely, by administrative access you
>>>>> mean I need to be able to log in to each of the resolvers (not
>>>>> administrative access on my local workstation to do a 'sudo dig
>>>>> example.net a +trace'), correct?
>>>>>
>>>>> A follow up question to that... is it even possible to perform  
>>>>> such
>>>>> a trace (revealing all resolvers) with the DNS protocol?
>>>>>
>>>>>
>>>>> 'tis not doable[0].
>>>>>
>>>>> What is the root problem that you are trying to solve here? Is  
>>>>> this
>>>>> just to know because you want to, or are you trying to solve a
>>>>> specific issue? In the very large majority of cases[1] your  
>>>>> machine
>>>>> is going to be querying whatever is configured in your resolv.conf
>>>>> (or equivalent) and those nameservers will go do the resolution  
>>>>> for
>>>>> you (as opposed to multiple levels of forwarders).
>>>>>
>>>>>
>>>>> [0]: I have horrid visions of someone responding back with some
>>>>> truly horrendous kludge that involves looking up random strings  
>>>>> and
>>>>> querying heaps-o-servers to see if any of them had cached the
>>>>> answer or something equally icky. Actually, you cloud see if the
>>>>> server that you query is the one that actually touches the auth
>>>>> server, but this is all ugly.
>>>>>
>>>>> [1]: No hard data here -- does anyone have any sort of guestimate
>>>>> on fraction of forwarded queries?
>>>>>
>>>>> W
>>>>>
>>>>>
>>>>> Or is this purely a designed limitation of dig?
>>>>> _______________________________________________
>>>>> bind-users mailing list
>>>>> bind-users at lists.isc.org
>>>>> https://lists.isc.org/mailman/listinfo/bind-users
>>>>>
>>>>>
>>>>>
>>>
>>> -- 
>>> Militant Agnostic--I don't know and you don't either...
>>>
>>>
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>>
>> --
>> Some people are like Slinkies......Not really good for anything but
>> they still bring a smile to your face when you push them down the
>> stairs.
>>
>>
>>
>
> --
> After you'd known Christine for any length of time, you found yourself
> fighting a desire to look into her ear to see if you could spot
> daylight coming the other way.
>
>     -- (Terry Pratchett, Maskerade)t
>
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