LinuxQuestions.org
LinuxAnswers - the LQ Linux tutorial section.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Distributions > Slackware
User Name
Password
Slackware This Forum is for the discussion of Slackware Linux.

Notices

Reply
 
Search this Thread
Old 05-15-2008, 09:59 AM   #1
skelter42
LQ Newbie
 
Registered: Jan 2008
Posts: 20

Rep: Reputation: 5
Slackware 12.1 with Static IP behind DHCP router resolves DNS verrrry slow. Help?


Hi folks,

First off, I wasn't sure whether to post here or in the Network forum. If I chose incorrectly, my appy polly loggies.

I have a Linksys WRT54G wireless router sitting behind a cable modem. Connected by wire to the router are my slack 12.1 box and 2 xp pro boxes. Wirelessly attached is a slack 12.0 laptop.

I am pretty newbish to all things linux, so bare with me.

In preparation of setting up the 12.1 box to be a samba server for file and print sharing, I changed all of the wired boxes to static IP addresses instead of having the router assign one. (The laptop will not have access to the samba shares, so it is remaining DHCP.) This was done with netconfig and assigning an IP outside of the router's DHCP range. (Unfortunately, my router doesn't have the option of assigning static addresses.)

My problem is this: the slack 12.1 box continues to connect to the internet, but the DNS resolution is now excruciatingly slow, around 45 seconds just to reach google. Ifconfig is fine, and when I ping the router the response is fine. Route takes several seconds to display the "default" connection.

In contrast, the xp boxes (amazingly) connect quickly with the static IP. Likewise, when used with DHCP mode the slack 12.1 box resolves quickly as well.

How can I fix this? (If possible?) My searches for answers have left me short. Thanks in advance!

skelter
 
Old 05-15-2008, 10:03 AM   #2
onebuck
Moderator
 
Registered: Jan 2005
Location: Midwest USA, Central Illinois
Distribution: SlackwareŽ
Posts: 11,292
Blog Entries: 3

Rep: Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447Reputation: 1447
Hi,

What do you have in '/etc/resolv.conf' for the static IP machines?
What do you have for your router DNS table?

You should use the DNS that your ISP provided. I like to have a fallback DNS by using third level DNS;

Code:
#Verizon Third level DNS
4.2.2.1
4.2.2.2
4.2.2.3
4.2.2.4
 
Old 05-15-2008, 10:14 AM   #3
skelter42
LQ Newbie
 
Registered: Jan 2008
Posts: 20

Original Poster
Rep: Reputation: 5
In resolv.conf:

Code:
search pneubie.org
nameserver 192.168.1.1
As far as my router DNS table goes, under "set up" there are text boxes to fill in static IP addresses for 3 DNS servers and a WINS server. These are currently all blank.

However, in the status section, two DNS servers are listed. I assume these are auto assigned by my ISP. How should I proceed?

Thanks!

skelter
 
Old 05-15-2008, 10:35 AM   #4
marnold
Member
 
Registered: Dec 2005
Distribution: Slackware64 14.1
Posts: 258

Rep: Reputation: 32
Quote:
Originally Posted by skelter42 View Post
In resolv.conf:

Code:
search pneubie.org
nameserver 192.168.1.1
As far as my router DNS table goes, under "set up" there are text boxes to fill in static IP addresses for 3 DNS servers and a WINS server. These are currently all blank.

However, in the status section, two DNS servers are listed. I assume these are auto assigned by my ISP. How should I proceed?
Edit the resolv.conf. Remove the existing nameserver line. Add in a nameserver line for each of those DNS IPs. Your DNS resolution woes will go away. I just figured this out yesterday myself.
 
Old 05-15-2008, 10:43 AM   #5
skelter42
LQ Newbie
 
Registered: Jan 2008
Posts: 20

Original Poster
Rep: Reputation: 5
Quote:
Edit the resolv.conf. Remove the existing nameserver line. Add in a nameserver line for each of those DNS IPs. Your DNS resolution woes will go away. I just figured this out yesterday myself.
That seemed like a logical solution to me too marnold, and I gave it a go. Unfortunately, no success. Thanks for the suggestion though!

skelter
 
Old 05-15-2008, 10:52 AM   #6
mcnalu
Member
 
Registered: Dec 2006
Location: Glasgow, UK
Distribution: Slackware 13.37 and 13.1
Posts: 393

Rep: Reputation: 63
I had a problem with ipv6 causing a timeout (on slackware 11 not 12.1 though).

The solution was to add the ipv6 module to the blacklist. lsmod as root will tell you whether it's loaded.
 
Old 05-15-2008, 11:07 AM   #7
skelter42
LQ Newbie
 
Registered: Jan 2008
Posts: 20

Original Poster
Rep: Reputation: 5
Quote:
I had a problem with ipv6 causing a timeout (on slackware 11 not 12.1 though).

The solution was to add the ipv6 module to the blacklist. lsmod as root will tell you whether it's loaded.
Mcnalu, ipv6 was indeed loaded. I had not blacklisted a module before, but a quick google taught me how.

Wonderfully, that did the trick. The interweb is performing swimmingly on my 12.1 machine now. Thank you!

And thank you onebuck and marnold!

skelter

P.S. I'll try to find out why that caused the problem and post back here when I do.
 
Old 05-15-2008, 11:16 AM   #8
mcnalu
Member
 
Registered: Dec 2006
Location: Glasgow, UK
Distribution: Slackware 13.37 and 13.1
Posts: 393

Rep: Reputation: 63
Skelter42, glad to hear it!

I believe the delay occurs because the DNS lookup is done the ipv6 way first, but because the server doesn't do ipv6, the request just times out. After this, an ipv4 request is sent and the server responds happily.

BTW I also had to comment out my router's IP as a DNS server in resolv.conf as it caused shorter, but very irritating delays.
 
Old 05-15-2008, 04:24 PM   #9
skelter42
LQ Newbie
 
Registered: Jan 2008
Posts: 20

Original Poster
Rep: Reputation: 5
After doing a tad of research it would appear that the cause of my problem is that my router, the Linksys WRT54G does not natively support ipv6.

But for anyone searching these forums and finding this post, here is an interesting bit I discovered (and probably everyone but me knew): the firmware for the WRT54G is open source and has been extensively hacked. There is quite a bit of free, reportedly reliable, firmware that turns this commodity router into more than it was meant to be. (I would hesitate to say enterprise level, but others don't.)

As I am a poor student and don't want to drop the coin to purchase a new router if I fry mine with alternate firmware, I don't intent to "upgrade" mine to use ipv6 and see if that solves the problem I had. But as soon as I can afford it I intend to.

cheers,

skelter
 
Old 05-15-2008, 06:05 PM   #10
T3slider
Senior Member
 
Registered: Jul 2007
Distribution: Slackware64-14.1
Posts: 2,265

Rep: Reputation: 649Reputation: 649Reputation: 649Reputation: 649Reputation: 649Reputation: 649
Well, ipv6 is really unnecessary right now since no servers really use it -- so you're OK disabling it for now (and for a fairly long time in the future). You won't even need to worry about it for quite some time now.
 
Old 05-16-2008, 09:17 AM   #11
marnold
Member
 
Registered: Dec 2005
Distribution: Slackware64 14.1
Posts: 258

Rep: Reputation: 32
skelter,

Thanks for the reminder about ipv6. I had meant to blacklist that module some time ago. I have no problem with about 99% of websites out there. The only one that I used frequently that gave me grief was the State Farm Bank site. After blacklisting that module, it is very snappy. I've only been meaning to do that for a couple of years now *cough*
 
Old 09-25-2009, 08:48 PM   #12
vik
Member
 
Registered: Apr 2008
Distribution: Gentoo
Posts: 225
Blog Entries: 8

Rep: Reputation: 50
Hey thanks a lot; blacklisting the ipv6 module worked for me too. Still applies to Slackware 13 in case anyone was interested.
 
  


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
How do I set up Slackware 9.1 to use DHCP with a static DNS? h00chman Linux - Newbie 2 12-18-2012 09:30 AM
DHCP static ip and NAMED (DNS) question Yaniv-Fer Linux - Networking 4 03-29-2006 06:55 AM
DSL via router: DHCP or static IP? Sinope Linux - Newbie 5 08-08-2004 04:18 PM
DNS resolves quickly but lynx extremely slow yichun Debian 2 07-01-2004 09:08 PM
DNS, NIS, Static <-> Dynamic DHCP, Proxy bjc Linux - Networking 5 11-12-2000 05:20 AM


All times are GMT -5. The time now is 12:56 PM.

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