LinuxQuestions.org
Register a domain and help support LQ
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 07-27-2006, 11:29 AM   #1
RAdams
Member
 
Registered: May 2006
Location: Cincinnati, Ohio
Distribution: Ubuntu
Posts: 256

Rep: Reputation: 30
Strange Delay when Resolving Domain Names ALMOST FIXED!


My work computer is connected via LAN cable directly to a router --> bridge --> cable modem setup on our small network. When I boot from Winblows, everything works as expected. However, on this Ubuntu installation, I'm getting a strange 3-10 second delay whenever I access an Internet resource, such as linuxquestions.org in my browser, or searching a repository, or pinging an external address. Now here's three weird points:
  1. I don't see this delay in Winblows on the same machine.
  2. Pinging google.com returns normal times for this connection (~30ms), but theres a longer than normal delay to begin pinging and return the results of each ping.
  3. Intranet resources work as fast as I expect them to.

What am I missing?

EDIT:
I discovered the root of the problem. It isn't in the accessing of the resources, but rather the resolution of the domain names. If I use my browser and go to google.com, there's about a 10 second delay. If I type in one of their IPs directly, it resolves instantly. So the problem is that Ubuntu is having trouble resolving domain names to IP addresses in a timely manner. I know how to fix this problem in Windows, but not Linux. How is this done?

Last edited by RAdams; 08-17-2006 at 11:58 AM.
 
Old 07-30-2006, 03:50 PM   #2
peter_robb
Senior Member
 
Registered: Feb 2002
Location: Szczecin, Poland
Distribution: Gentoo, Debian
Posts: 2,458

Rep: Reputation: 47
I have seen some systems send ident probes out on tcp port 135 before connecting to services.. Coz they're never answered, it creates a 3-5 sec delay..

Make an iptables LOG rule to check,eg
iptables -t nat -I POSTROUTING -o eth0 -p tcp --dport 135 -j LOG --log-prefix "ident "

If there are, make a rule to reject them, eg
iptables -I OUTPUT -p tcp --dport 135 -j REJECT --reject-with tcp-reset

Last edited by peter_robb; 07-30-2006 at 03:53 PM.
 
Old 08-14-2006, 02:22 PM   #3
RAdams
Member
 
Registered: May 2006
Location: Cincinnati, Ohio
Distribution: Ubuntu
Posts: 256

Original Poster
Rep: Reputation: 30
Quote:
Originally Posted by peter_robb
I have seen some systems send ident probes out on tcp port 135 before connecting to services.. Coz they're never answered, it creates a 3-5 sec delay..

Make an iptables LOG rule to check,eg
iptables -t nat -I POSTROUTING -o eth0 -p tcp --dport 135 -j LOG --log-prefix "ident "

If there are, make a rule to reject them, eg
iptables -I OUTPUT -p tcp --dport 135 -j REJECT --reject-with tcp-reset
I wasn't sure how to check the log I created with your first command, so I just tried making the rule. Unfortunatlely, I'm still experiencing a delay... If anything, it's slightly longer.
 
Old 08-17-2006, 12:32 AM   #4
RAdams
Member
 
Registered: May 2006
Location: Cincinnati, Ohio
Distribution: Ubuntu
Posts: 256

Original Poster
Rep: Reputation: 30
Not to be a thread-bumper, but does anyone have any ideas as to what to try next?
 
Old 08-28-2006, 09:38 AM   #5
RAdams
Member
 
Registered: May 2006
Location: Cincinnati, Ohio
Distribution: Ubuntu
Posts: 256

Original Poster
Rep: Reputation: 30
Only because this thread has been placed rather high on google when using the terms ubuntu domain names delay, I thought I'd take the time to link to the solution to this problem, in case someone else faces this issue in the future:

Code:
sudo gedit /etc/modprobe.d/bad_list
Add the following to the document that opens (it will likely be empty):
Code:
# Added to disable IPV6
alias net-pf-10 off
Then go to http://ubuntu.wordpress.com/2006/08/...ster-browsing/ and follow the instructions there. I recommend that step even if you ARE using ipv6 protocols on your network.
 
  


Reply

Tags
connection, delay, dns, ipv6


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
internet activity delay MacDahlin Linux - Software 4 04-17-2006 08:12 AM
Accessing Internet DanTaylor Programming 2 03-09-2006 12:04 AM
Internet routing delay zCut Linux - Newbie 10 03-07-2006 01:13 PM
A strange delay when start-up LinxNew Linux - Laptop and Netbook 1 04-29-2005 09:44 AM
Accessing the internet ruitao Linux - General 2 03-05-2003 06:27 PM


All times are GMT -5. The time now is 11:50 AM.

Main Menu
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
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration