dig +trace to find all the forwarders?

Warren Kumari warren at kumari.net
Mon Apr 26 18:20:21 UTC 2010


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...
>
>
> _______________________________________________
> bind-users mailing list
> bind-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/bind-users
>
> Proud partner. Susan G. Komen for the Cure.
>
> Please consider our environment before printing this e-mail or  
> attachments.
> ----------------------------------
> CONFIDENTIALITY NOTICE: This e-mail may contain privileged or  
> confidential information and is for the sole use of the intended  
> recipient(s). If you are not the intended recipient, any disclosure,  
> copying, distribution, or use of the contents of this information is  
> prohibited and may be unlawful. If you have received this electronic  
> transmission in error, please reply immediately to the sender that  
> you have received the message in error, and delete it. Thank you.
> ----------------------------------

--
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.






More information about the bind-users mailing list