UDNS issue

[Abhijit Pandey]

Hi,


If it is attached is more data. Host followed by dnsget.
Looks to me the first time they return correctly.
Second time even host has issues. Attached is wireshark pcap.

Abhijit




[apandey at localhost ~]$ host -v www.hotmail.com
Trying "www.hotmail.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61273
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.hotmail.com.		IN	A

;; ANSWER SECTION:
www.hotmail.com.	1484	IN	CNAME	mail.live.com.
mail.live.com.		2510	IN	A	207.46.11.121
mail.live.com.		2510	IN	A	64.4.38.249
mail.live.com.		2510	IN	A	207.46.10.121
mail.live.com.		2510	IN	A	207.46.8.121
mail.live.com.		2510	IN	A	207.46.8.249
mail.live.com.		2510	IN	A	207.46.9.121
mail.live.com.		2510	IN	A	207.46.9.249
mail.live.com.		2510	IN	A	207.46.11.249
mail.live.com.		2510	IN	A	65.55.130.121
mail.live.com.		2510	IN	A	65.55.131.121
mail.live.com.		2510	IN	A	65.55.132.121
mail.live.com.		2510	IN	A	207.46.10.249

Received 249 bytes from 192.168.15.1#53 in 16 ms
Trying "mail.live.com"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56277
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;mail.live.com.			IN	AAAA

;; AUTHORITY SECTION:
mail.live.com.		115	IN	SOA	ns1.msft.net. msnhst.microsoft.com.
2009012802 1800 900 2419200 3600

Received 96 bytes from 192.168.15.1#53 in 11 ms
Trying "mail.live.com"
;; connection timed out; no servers could be reached
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$
[apandey at localhost ~]$ dnsget -v www.hotmail.com
;; trying www.hotmail.com.
;; sending 44 bytes query to 192.168.15.1 port 53

;; received 60 bytes response from 192.168.15.1 port 53
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4833, size: 60
;; flags: qr rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUERY SECTION (1):
;www.hotmail.com.		IN	A

;; ANSWER section (1):
;EDNS0 OPT record (UDPsize: 4096): 0 bytes

;; ADDITIONAL section (1):
www.hotmail.com.	10000	IN	A	207.46.11.121

dnsget: unable to lookup A record for www.hotmail.com: valid domain
but no data of requested type
[apandey at localhost ~]$
[apandey at localhost ~]$ dnsget -v www.hotmail.com
;; trying www.hotmail.com.
;; sending 44 bytes query to 192.168.15.1 port 53

;; received 60 bytes response from 192.168.15.1 port 53
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50433, size: 60
;; flags: qr rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; QUERY SECTION (1):
;www.hotmail.com.		IN	A

;; ANSWER section (1):
;EDNS0 OPT record (UDPsize: 4096): 0 bytes

;; ADDITIONAL section (1):
www.hotmail.com.	10000	IN	A	207.46.11.121

dnsget: unable to lookup A record for www.hotmail.com: valid domain
but no data of requested type



On Tue, Feb 3, 2009 at 10:05 PM, Abhijit Pandey <abhijpandey at gmail.com> wrote:
> Hi Michael,
>
> I have a comcast cable at home for internet.
>
> When I connect directly, to the modem, queries through comcast
> provided DNS servers work correctly.
>
>
> Otherwise I go through the following router to the Comcast Modem
> This router does NAT, becomes DNS proxy, and becomes the nameserver in
> /etc/resolv.conf
>
> Firmware Version: 1.00.62
> Wireless-G Broadband Router with 2 Phone Ports          WRTP54G
>
> Let me know if you need any further information.
> Abhijit
>
>
>
>
> On Tue, Feb 3, 2009 at 12:05 AM, Michael Tokarev <mjt+udns at corpit.ru> wrote:
>> Abhijit Pandey wrote:
>>> Hi Michael,
>>>
>>> Setting $ RES_OPTIONS="udpbuf=512" ./dnsget ...   did solved the problem.
>>
>> Well, as I predicted.  But how about my question - what resolver
>> do you have, which software/brand/version?
>>
>>> I was using Rich formatting of Gmail, which probably your E-mail
>>> client didn't understand.
>>
>> My client understands html, but your mail client decided to add
>> html link tags around every word with at least one dot in it,
>> "thinking" it is an URL which it is not.  Like all domain names
>> we were querying.
>>
>>> I am investigating using UDNS for asynchronous queries(A and TXT
>>> records), in a production environment for heavy loads.
>>> dnsget seems to give a fairly good idea, of how to use the API's
>>
>> Well, the API and the whole thing is simple enough to be useful,
>> I think.  It was one of the library's main goals: easy to use
>> interface.
>>
>>> I see UDNS is being used in various distributions(Gentoo/Ubuntu/Fedora etc).
>>> Hopefully I wouldn't any bugs to fix.
>>
>> Let's hope so.. ;)  The only problem I know of is the one you
>> faced already: sometimes the library is unable to work because
>> some resolver nearby does not understand or does not properly
>> implement EDNS0 extensions (which are turned off using the above
>> workaround).  Unfortunately, in all such cases I know (about 3
>> or 4 reports so far) no one replied to me telling which software
>> it is that's broken.  You too ignored my question of that sort...
>> It'd be VERY interesting to know which software misbehaves with
>> EDNS0 extensions in use.  Thanks!
>>
>> /mjt
>>
>