Q: what's more annoying than top posting?
A: full quoting bottom posters.

On Nov 19, 2009, at 12:57 PM, stan <stanb@panix.com> wrote:

quoted text
> On Thu, Nov 19, 2009 at 03:08:25PM -0500, Dave Anderson wrote:
>> On Thu, 19 Nov 2009, stan wrote:
>>
>>> On Thu, Nov 19, 2009 at 11:24:44AM -0500, Dave Anderson wrote:
>>>> On Thu, 19 Nov 2009, stan wrote:
>>>>
>>>>> On Wed, Nov 18, 2009 at 11:03:27PM -0500, Dave Anderson wrote:
>>>>>> On Wed, 18 Nov 2009, stan wrote:
>>>>>>
>>>>>>> On Wed, Nov 18, 2009 at 05:00:02PM -0500, Dave Anderson wrote:
>>>>>>>> On Wed, 18 Nov 2009, stan wrote:
>>>>>>>>
>>>>>>>>> Can anyone xplain this behavior to me?
>>>>>>>>
>>>>>>>> Without access to your nameservers it's not possible to be  
>>>>>>>> sure, but see
>>>>>>>> below -- this looks normal to me.
>>>>>>>>
>>>>>>>>> Given the following resolv.conf file:
>>>>>>>>>
>>>>>>>>> root@pm3fw:root# cat /etc/resolv.conf
>>>>>>>>> lookup file bind
>>>>>>>>> search mcn.chs kapstonepaper.com pm3.charleston.meadwestvaco.com
>>>>>>>>> nameserver 127.0.0.1
>>>>>>>>> nameserver 10.209.128.20
>>>>>>>>> nameserver 10.209.128.26
>>>>>>>>> nameserver 10.209.142.158
>>>>>>>>>
>>>>>>>>> And:
>>>>>>>>>
>>>>>>>>> root@pm3fw:root# nslookup
>>>>>>>>>> cvsup
>>>>>>>>> Server:         127.0.0.1
>>>>>>>>> Address:        127.0.0.1#53
>>>>>>>>>
>>>>>>>>> Non-authoritative answer:
>>>>>>>>> Name:   cvsup.mcn.chs
>>>>>>>>> Address: 10.209.142.151
>>>>>>>>>> 10.209.142.151
>>>>>>>>> Server:         127.0.0.1
>>>>>>>>> Address:        127.0.0.1#53
>>>>>>>>>
>>>>>>>>> 151.142.209.10.in-addr.arpa     name = cvsup.meadwestvaco.com.
>>>>>>>>>> exit
>>>>>>>>>
>>>>>>>>> Why does this happen ? And how?
>>>>>>>>
>>>>>>>> You apparently have a system with multiple names and a single  
>>>>>>>> IP
>>>>>>>> address.  Both cvsup.mch.chs and cvsup.meadwestvaco.com are  
>>>>>>>> assigned
>>>>>>>> address 10.209.142.151, but the reverse-lookup entry can't  
>>>>>>>> return both
>>>>>>>> names.  Given the order of domains in your 'search' directive,
>>>>>>>> cvsup.mcn.chs is looked up first and so is the name that  
>>>>>>>> nslookup
>>>>>>>> reports, but cvsup.meadwestvaco.com was chosen as the  
>>>>>>>> 'official' name
>>>>>>>> for the reverse lookup by whoever set up your DNS.
>>>>>>>>
>>>>>>> Your analysis is correct, in that thier are multiple names  
>>>>>>> (don't ask :-().
>>>>>>> I have control of some of the nameservers. They are bind 9 on  
>>>>>>> OpenBSD, can
>>>>>>> you clarify what you mean by "offical name" are you talking  
>>>>>>> about a A
>>>>>>> entry, as oposed to a CNAME entry?
>>>>>>
>>>>>> Sorry I wasn't clear.  I was referring to the *.in-addr.arpa  
>>>>>> 'PTR' DNS
>>>>>> entry which provides the translation from IPv4 address to host  
>>>>>> name.
>>>>>
>>>>> K, I am starting to understand this now, thequestion is how to  
>>>>> fix it. I do
>>>>> have a PTR record in my 10.in-addr.arpa db. If I wan this NOT to  
>>>>> be the
>>>>> authortative entry for this IP -> name tarnsaltion, so that an  
>>>>> authortative
>>>>> eoll 'pass on by" this Bind instnace and go on to one further  
>>>>> down, how can
>>>>> I acomplis htis?
>>>>
>>>> If I'm understanding you correctly, you can't.  The only control  
>>>> which I
>>>> recall offhand that you have over whether a nameserver responds  
>>>> with
>>>> data from its cache is to set the 'authoritative' flag in your  
>>>> request,
>>>> which will cause a nameserver with only cached data to pass the  
>>>> request
>>>> on -- but you don't want to do this routinely since it defeats the
>>>> distributed nature of DNS and so results in overloading the
>>>> authoritative servers.
>>>>
>>>> All that the 'authoritative' flag tells you is whether the  
>>>> response came
>>>> from a server with the entry in its cache (not authoritative) or  
>>>> from
>>>> one which has that information manually configured on it
>>>> (authoritative) -- so I'm not at all sure what you mean by 'fix  
>>>> it'.
>>>>
>>>> What exactly is the behavior that you want?
>>>>
>>> I would like to have all programs get the same results as  
>>> nslookup, that is
>>> get *.mcn.chs for the reverese lookup from this machine. I have  
>>> other
>>> machines configureddiferently in resolv.conf that I want to get the
>>> *.meadwestvaco.com resolution. This has been a long a painful  
>>> taril, and I
>>> thoguht I had what I wanted based upon using nslookup as a test.  
>>> When I saw
>>> diffeent software (nmap in this case) getting diferent resolutin,  
>>> it was
>>> verry disapointiing.
>>
>> Um, nslookup doesn't get e.g. cvsup.mcn.chs as the reverse lookup  
>> -- it
>> just finds that name first when looking up 'cvsup' because of the  
>> order
>> in which you specified domains in the 'search' directive in your
>> resolv.conf.  When you asked nslookup for a reverse lookup of
>> 10.209.142.151 it returned cvsup.meadwestvaco.com just like  
>> everything
>> else did.
>>
>> The 'reverse lookup' for a.b.c.d by definition returns the value of  
>> the
>> PTR record(s) with label d.c.b.a.in-addr.arpa.  Barring DNS spazzes,
>> this will be the same no matter which machine issues the request.   
>> Well,
>> normally.  There is one special case I'm aware of -- if you configure
>> your nameservers with 'split-horizon' DNS, they can return different
>> information depending on the IP address range from which the request
>> originates.
>>
> Thanks for the patient explanation.
>
> I am an idiot.
>
> -- 
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?