LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 02-04-2009, 03:17 AM   #1
jimdaworm
Member
 
Registered: Aug 2003
Location: Spain
Distribution: Ubuntu
Posts: 895

Rep: Reputation: 30
Strange DNS replies.


Hi Everyone,

I have been trying to troubleshoot some 404 errors I have been getting sometimes/randomly when I am trying to update aptitude.

Can anyone explain the below?

Code:
debby:/home/adam# traceroute http.us.debian.org
traceroute to http.us.debian.org (78.141.176.35), 30 hops max, 60 byte packets
 1  mygateway1.ar7 (10.0.0.1)  1.445 ms  1.751 ms  1.989 ms
 2  * * *
 3  145.Red-80-58-121.staticIP.rima-tde.net (*.*.*.*)  332.033 ms  332.949 ms  333.766 ms
 4  So6-0-0-0-grtmadpe3.red.telefonica.wholesale.net (84.16.8.121)  334.691 ms  335.445 ms  346.164 ms
 5  So6-3-0-0-grtparix3.red.telefonica-wholesale.net (84.16.12.118)  373.668 ms  374.722 ms So7-0-0-0-grtparix3.red.telefonica-wholesale.net (213.140.37.18)  388.364 ms
 6  Tiscali-7-1-0-0-grtparix3.red.telefonica-wholesale.net (213.140.53.146)  389.319 ms  383.656 ms  396.974 ms
 7  xe-0-0-0.fra20.ip.tiscali.net (89.149.186.65)  397.864 ms  128.508 ms xe-2-0-0.fra20.ip.tiscali.net (89.149.186.73)  128.677 ms
 8  ptlu-gw.ip.tiscali.net (213.200.64.58)  342.638 ms  342.892 ms  343.327 ms
 9  213.166.61.206 (213.166.61.206)  117.650 ms  93.723 ms  97.923 ms
10  download.skype.com (78.141.176.35)  203.168 ms  203.403 ms  203.735 ms
debby:/home/adam#
Code:
debby:/home/adam# ping http.us.debian.org
PING http.us.debian.org (78.141.176.35) 56(84) bytes of data.
64 bytes from download.skype.com (78.141.176.35): icmp_seq=1 ttl=50 time=101 ms
64 bytes from download.skype.com (78.141.176.35): icmp_seq=2 ttl=50 time=96.3 ms
64 bytes from download.skype.com (78.141.176.35): icmp_seq=3 ttl=49 time=124 ms
64 bytes from download.skype.com (78.141.176.35): icmp_seq=4 ttl=51 time=96.2 ms
64 bytes from download.skype.com (78.141.176.35): icmp_seq=5 ttl=49 time=97.8 ms
64 bytes from download.skype.com (78.141.176.35): icmp_seq=6 ttl=50 time=96.9 ms
^C
--- http.us.debian.org ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5026ms
rtt min/avg/max/mdev = 96.201/102.139/124.373/10.082 ms
debby:/home/adam#
This is what I got from an online website when I asked it to ping the same url:

Code:
--- PING http.us.debian.org (35.9.37.225) 56(84) bytes of data. ---
64 bytes from ike.egr.msu.edu (35.9.37.225): icmp_seq=1 ttl=53 time=117 ms
64 bytes from ike.egr.msu.edu (35.9.37.225): icmp_seq=2 ttl=53 time=119 ms
64 bytes from ike.egr.msu.edu (35.9.37.225): icmp_seq=3 ttl=53 time=118 ms
64 bytes from ike.egr.msu.edu (35.9.37.225): icmp_seq=4 ttl=53 time=118 ms
 
Old 02-04-2009, 04:08 AM   #2
bathory
LQ Guru
 
Registered: Jun 2004
Location: Piraeus
Distribution: Slackware
Posts: 12,505

Rep: Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769Reputation: 1769
It seems that the dns used in the second case is the correct one:
Code:
 dig http.us.debian.org

; <<>> DiG 9.6.0-P1 <<>> http.us.debian.org
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36028
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 3, ADDITIONAL: 0

;; QUESTION SECTION:
;http.us.debian.org.            IN      A

;; ANSWER SECTION:
http.us.debian.org.     300     IN      A       64.50.238.52
http.us.debian.org.     300     IN      A       128.30.2.36
http.us.debian.org.     300     IN      A       35.9.37.225
http.us.debian.org.     300     IN      A       64.50.236.52

;; AUTHORITY SECTION:
debian.org.             1428    IN      NS      raff.debian.org.
debian.org.             1428    IN      NS      rietz.debian.org.
debian.org.             1428    IN      NS      klecker.debian.org.

;; Query time: 112 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Feb  4 12:04:29 2009
;; MSG SIZE  rcvd: 161
Check your /etc/resolv.conf and use another dns that is more reliable than the one you use now.

Regards
 
Old 02-04-2009, 04:31 AM   #3
rossonieri#1
Member
 
Registered: Jun 2007
Posts: 359

Rep: Reputation: 34
hi jim,

Quote:
--- PING http.us.debian.org (35.9.37.225) 56(84) bytes of data. ---
64 bytes from ike.egr.msu.edu (35.9.37.225): icmp_seq=1 ttl=53 time=117 ms
64 bytes from ike.egr.msu.edu (35.9.37.225): icmp_seq=2 ttl=53 time=119 ms
you mean why there are 2 different hostname?
its a normal behavior since any internet DNS record doesnt have to be match with a real target name.

so it - for example : the ike.egr.msu.edu is the real target hostname - could be translated to any name on the internet DNS record like http2.us.debian.org, http3.us.debian.org but they still use the same real target host - which is ike.egr.msu.edu.

and, what you've pinged is the real target which answer it.

and bathory has given you a better resolution to try changing the DNS server for better name resolution.

HTH.

Last edited by rossonieri#1; 02-04-2009 at 04:35 AM. Reason: addition
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
scanning for replies to replies pixellany LQ Suggestions & Feedback 2 04-10-2008 10:22 AM
Really strange DNS problems... FlyingMoose Linux - Networking 8 09-03-2007 07:32 PM
strange DNS vadirajcs Linux - Wireless Networking 3 07-27-2006 06:03 AM
Strange DNS problem JonCooperUK Slackware 3 04-02-2004 12:09 PM
Strange dns problem jekyl Linux - Networking 1 01-15-2003 12:49 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 01:14 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration