Tech-101 Free Computer Support Tech-101 Free Computer Support

Home Forum FAQs Terms of Service
Go Back   Tech-101 Free Computer Support > Hardware > Networking
Connect with Facebook

Closed Thread
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 04-23-2009, 07:51 PM
jobeard's Avatar
Site Admin

 
Join Date: Dec 2008
Location: Southern Calif.
Posts: 1,190
Default [solved] is a puzzlement: nslookup appending domain.name

Lets start with http://www.google.com is at 208.67.219.231
see for yourself http://208.67.219.231/

now then, my ipconfig /all reports[indent:2588ne5t]Windows IP Configuration
Host Name . . . . . . . . . . . . : ltbeard
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : socal.rr.com

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : socal.rr.com
Description . . . . . . . . . . . : Realtek RTL8139/810x Family Fast Eth
ernet NIC
Physical Address. . . . . . . . . : 00-xx-yy-3D-zz-00
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.0.4
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 208.67.222.222
208.67.222.220
Primary WINS Server . . . . . . . : 192.168.0.4
Lease Obtained. . . . . . . . . . : Wednesday, April 22, 2009 8:29:17 AM

Lease Expires . . . . . . . . . . : Monday, January 18, 2038 8:14:07 PM[/indent:2588ne5t]
(yes, the DNS addresses are for the OpenDNS servers but the symptom below was present even with the original ISP dns addresses)

First, ping http://www.google.com works well as does the http: shown above.
HOWEVER,
[sample:2588ne5t]C:\Documents and Settings\Jeff>nslookup http://www.google.com
Server: resolver1.opendns.com
Address: 208.67.222.222

Non-authoritative answer:
Name: http://www.google.com.socal.rr.com
Address: 208.67.216.132[/sample:2588ne5t]the addition of the suffix forces the lookup to return
an address related to the DNS: 208.67.216.132


(use the default DNS addresses and the same thing happens).

substitute the google ip addres and we get a reasonable reply[sample:2588ne5t]C:\cygwin\home\Jeff>nslookup 208.67.219.231
Server: resolver1.opendns.com
Address: 208.67.222.222

Name: google.navigation.opendns.com
Address: 208.67.219.231[/sample:2588ne5t]

NSLOOKUP is bypassing the resolve mechanism whereas ping and everyone else
applies it correctly, even a perl script [sample:2588ne5t]C:\cygwin\home\Jeff>iplookup.pl http://www.google.com
http://www.google.com -> 208.67.219.231 which is correct[/sample:2588ne5t]

I believe that the Connection-specific DNS Suffix . : socal.rr.com is causing the issue,
but can't seem to get it removed sucessfully. This has been a long standing issue which
I've just ignored (btw: which also prompted the writing of the iplookup.pl script ).

Anyone with ideas?
The proper response from nslookup domain.name -> is the ip address assigned that domain
__________________
J. O. Beard; you + tech-101.com => synergism. Secure your system now

Last edited by jobeard; 10-31-2009 at 01:53 PM. Reason: solved next comment
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!twitterShare on Facebook
  #2 (permalink)  
Old 04-27-2009, 08:45 PM
Blind Dragon's Avatar
Site Admin

 
Join Date: Dec 2008
Location: Florida
Posts: 1,498
Send a message via MSN to Blind Dragon Send a message via Yahoo to Blind Dragon Send a message via Skype™ to Blind Dragon
Default Re: is a puzzlement: nslookup appending domain.name

I think I understand. This is not my strongest subject

Nslookup will always devolve the name from the current context. If you fail to fully qualify a name query (that is, use trailing dot), the query will be appended to the current context.

In your example, the current DNS settings are social.rr.com and a query is performed on http://www.google.com; the first query will go out as http://www.google.com.social.rr.com because of the query being unqualified.

The trailing dot makes the domain name absolute and technically unambiguous. No software is expected to append anything to such a domain name when looking it up in DNS. With the absence of the trailing dot, some software may theoretically attempt to append one or more suffixes and the consequences can range from harmless redundant lookups to potentially dangerous lookups of things that are not meant to be looked up.

I believe you can simply use a Fully Qualified Domain Name (that is, add the trailing dot to the name).
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!twitterShare on Facebook
  #3 (permalink)  
Old 04-27-2009, 10:02 PM
jobeard's Avatar
Site Admin

 
Join Date: Dec 2008
Location: Southern Calif.
Posts: 1,190
Default Re: is a puzzlement: nslookup appending domain.name

UNBELIEVABLE! Now teach me where you found or got this insight!!!

case #1[sample:3l40d2ep]C:\Documents and Settings\nMaster>nslookup http://www.google.com.
Server: resolver1.opendns.com
Address: 208.67.222.222

Non-authoritative answer:
Name: google.navigation.opendns.com
Addresses: 208.67.219.231, 208.67.219.230 << real google.com addresses
Aliases: http://www.google.com[/sample:3l40d2ep]
case #2[sample:3l40d2ep]C:\Documents and Settings\nMaster>nslookup http://www.google.com
Server: resolver1.opendns.com
Address: 208.67.222.222

Non-authoritative answer:
Name: http://www.google.com.socal.rr.com
Address: 208.67.216.132 << part of OpenDNS [/sample:3l40d2ep]
__________________
J. O. Beard; you + tech-101.com => synergism. Secure your system now
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!twitterShare on Facebook
  #4 (permalink)  
Old 04-27-2009, 11:15 PM
Blind Dragon's Avatar
Site Admin

 
Join Date: Dec 2008
Location: Florida
Posts: 1,498
Send a message via MSN to Blind Dragon Send a message via Yahoo to Blind Dragon Send a message via Skype™ to Blind Dragon
Default Re: is a puzzlement: nslookup appending domain.name

I don't know for sure. I had notes on it from various sites, because i was having DNS problems a while back.
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!twitterShare on Facebook
Closed Thread

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 12:48 PM.

Copyright © 2009 Tech-101.com. All rights reserved.

Tech-101 Free Computer Support Tech-101 Free Computer Support