name resolution failing for most domain names, a few are resolving

Posted on 2006-03-24
Last Modified: 2010-03-18
I was having slow browser response in my Suse 10 system and discovered that of the three DNS servers I had listed the first was failing which cause slow name resolution even though once connected the connection was fast. I commented out the first DNS server in /etc/resolv.conf and everything was great for the next couple of days then suddenly my browser and email client started reporting  "<domain-name> could not be found" errors for most sites. A few sites, the ones I visit regularly, still work but most don't. I've checked everything I know to check (which isn't a lot I'm afraid). My Linux box is behind two Linksys routers (a voip router and a wireless access point). I don't believe these are the problem because my Windows machine is behind the same two routers and works fine.  The /etc/resolv.conf files contains references to the same DNS servers as the Windows box. The default gateway on the linux box is also set the same as the Windows box. I'm out of ideas and would appreciate any help you can give me.
Question by:udysisx
    LVL 3

    Accepted Solution

    If the sites don't change, you can get buy for a brief time by sticking them in your /etc/hosts

    I'm not sure whether installing a caching DNS server on your machine will help...on my
    lan I have a linux machine acting as a firewall to my cable modem -- and I have a DNS server
    on my can install a caching dns server as an rpm package (I never have).

    If your DNS server works for some sites and doesn't work for other sites, the server has
    problems...Also problems are often intermittent -- a problem once can be ignored...a series
    of problems is different...

    I'm a bit confused because you say your windows machine works fine...

    When there is a difference, the configuration/order is different.

    It may be useful to physically check the packets (using ethereal) to confirm the same packets are being transmitted...


    Author Comment

    What do you mean by "When there is a difference, the configuration/order is different."?
    My DNS servers are my ISP's DNS servers so that fact that the windows machine works
    and shares the same DNS servers is an indication that the DNS servers and the path to
    them (ie my two routers) are all working OK. Is there any sort of caching already going on
    in a basic setup. The fact that a hand full of my regularly visited sites still work seems like
    an indication that they have been cached.  I'll try using ethereal to see what's going where.

    Author Comment

    Well, ethereal proved to be a good idea. Not so much for the packets but for the following warning message that it displayed on my xterm...

    adns: server is not willing to do recursive lookups for us (Q, QTYPE=PTR(checked), NS=
    adns: server is not willing to do recursive lookups for us (QNAME=, QTYPE=PTR(checked), NS=

    Apparently windows doesn't ask for a recursive lookup or doesn't care.

    In any case, I put a different set of DNS servers into /etc/resolv.conf and that seems to have solved
    the problem.  Thanks for your help it got me going again.

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    How to improve team productivity

    Quip adds documents, spreadsheets, and tasklists to your Slack experience
    - Elevate ideas to Quip docs
    - Share Quip docs in Slack
    - Get notified of changes to your docs
    - Available on iOS/Android/Desktop/Web
    - Online/Offline

    I have seen several blogs and forum entries elsewhere state that because NTFS volumes do not support linux ownership or permissions, they cannot be used for anonymous ftp upload through the vsftpd program.   IT can be done and here's how to get i…
    Note: for this to work properly you need to use a Cross-Over network cable. 1. Connect both servers S1 and S2 on the second network slots respectively. Note that you can use the 1st slots but usually these would be occupied by the Service Provide…
    It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages.
    In this sixth video of the Xpdf series, we discuss and demonstrate the PDFtoPNG utility, which converts a multi-page PDF file to separate color, grayscale, or monochrome PNG files, creating one PNG file for each page in the PDF. It does this via a c…

    794 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    17 Experts available now in Live!

    Get 1:1 Help Now