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Connection ok once established; "cannot find server or DNS error" most of the rest of the time

Hi Experts,

Can anyone help me diagnose a problem with my DSL? It's from Qwest, and of course their tech support is absolutely useless.

The problem is this: most of the time, I get a "cannot find server or DNS error" from my browser. However, once a connection has been established, I can usually surf just fine. E.g., I can only get into launch.com about one time in ten tries. However, once I've got a connection, I can stream music for hours no problem. If I shut everything down, and do try to reconnect, I have just the same problem.

Even while music is streaming, I just get all the same problems with other websites, including launch.com.

Could anyone give me some clues as to what is going on, and how I might diagnose the problem, given I only access to this ropey connection?

The service used to fine up to week ago. I have reproduced ths behavior on 3 computers.
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metalaureate
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metalaureate
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2 Solutions
 
rtptucksCommented:
ok heres a few things to do

Check to make sure youre itnernet isnt going through a proxy server - control panle >Internet options> connections > proxy

Make sure this is empty, youre ISP might want you to be going through their proxy,

When you experience problems goto start>run>cmd and when the dos panel is up type nslookup
this will do name server lookup to youre dns server then type any domain ur getting problems with, if you recieve an ip address back then youre dns is ok and it might be an Internet explorer problem or if you dont get a reply then the dns wont work ..

If that is the case goto Network connections  > tcp/ip properties > leave the ip address and subnet etc to dynamic but change the DNS to these -
195.92.195.94
195.92.195.95

Then try again.

If its an internet explorer problem try this aswell because ive seen it work
http://www.mozilla.org/products/firefox/download.html?http%3A//ftp.mozilla.org/pub/mozilla.org/firefox/releases/0.9.3/FirefoxSetup-0.9.3.exe
this is firefox (mozilla) and ive seen IE not work and firefox work

Cheers
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Fatal_ExceptionSystems EngineerCommented:
This could also be the result of incorrect MTU settings...  Read the article I have written on this from my website:

www.doverproductions.com

Look under Broadband Cable and DSL for the Adjust Your MTU Size article..   I think I have explained it fairly well there, as well as tips on troubleshooting this problem..

One thing to remember with DSL..  It is not an Always On situation, whereas Cable is..  

FE
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metalaureateAuthor Commented:
NSLOOKUP is always ok, at least, it always returns a bunch of IP addresses. The problem I have obtains to IE, Mozilla, Firefox, Eudora, NS 7.1 etc., on 3 machines, all of which worked fine up until 5 days ago, so not an IE problem.

This has led to a new fact: in 99% of cases I try, it is fine if I access a website via its IP address; when I switch to its domain name, then the problem occurs.
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metalaureateAuthor Commented:
Thanks FE -- I'll look into that, but can it be problem when my connection has been fine for 10 months, and his problem only just started occurring? If MTU size were the problem, wouldn't I have always had this problem?
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Fatal_ExceptionSystems EngineerCommented:
If you can access these sites fine with the IP address, then you are correct..  It is a problem with name resolution...  You might try a different DNS server for the next step..  Any of them would do..

FE
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Fatal_ExceptionSystems EngineerCommented:
Heck, for that matter, you could use one of mine...  just for testing..

24.95.80.41
24.95.80.49
65.24.0.163
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rtptucksCommented:
Yeah as above i did give you 2 DNS servers to change in your network configuration..

Try a differnt DNS and lets take it from there! :)
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metalaureateAuthor Commented:
Well, you both rock, all is fine now!

I have some DNS servers I can use; but to be clear, the diagnosis is.. wha? Qwest's default nameservers are a heap of scrap?
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Fatal_ExceptionSystems EngineerCommented:
Very well could be...   Qwest has gone downhill in my opinion, and it could be their support team maintaining their networks have been outsourced...  :)

rpt..  did not see that you provided those external DNS addresses..  sorry..

and thanks..

FE
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