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DNS not working.

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cwinnyk

Programmer
May 27, 2003
62
US
Hey everyone. I've tried everything I can think of to fix this problem. So, before I reinstall windows, I'll as the experts here as my last shot.

My friend just got cable internet the other day. Previously, he was using dialup via MSN without having too many problems. However, when he plugs the cable modem into his internet router, he can't get any of his internet applications to work. I beleive this has something to do with DNS, because when I run IPCONFIG, he has the right IP address and gateway. He even has some DNS servers listed. If we ping Yahoo's IP address, it will respond to me. However, if I ping it will gie me an unknown host error. I added and their IP address to his HOSTS file. I ran another ping " and this time it worked. However, when i type on his IE, and it still gives us a DNS error. AOL IM and WinMX won't work either. I've checked all his DNS, WINS, DHCP, and IP properties, and they all seem correct. Dell and OptOnline Internet is telling him to reformat his computer. Does anyone have any ideas?

Thanks for your help.

Chris
 
When you run an IPCONFIG /ALL the DNS servers listed, are they the correct ISP DNS servers? I don't think reloading is necessary to fix a DNS isssue. Can you ping the DNS servers listed? Are they listed by name or IP?
Wait, just reread the post. Does it work if you do not have the router connected? If so, the router has the wrong DNS servers in its configuration. Connect straight to the cable modem, do an IPCONFIG /ALL, note the DNS servers listed, then enter them into your router and try again....

Thanks,

Matt Wray
MCSE, MCSA, MCP, CCNA

 
hey. He's not using a Router. The DNS servers come up as IP addresses, and, yes, I can ping them. I tried to manually set them in The IP properties also, but that didn't work....

Oh, I saw what you meant by when you were referring to router. I haven't finished my first cup of coffee yet this morning. :) Let me rephrase.

"However, when he plugs the cable modem into his NIC CARD, he can't get any of his internet applications to work."

I'm sorry...I'm braindead I guess, hehe.
 
Matrox has some good products that support mutiple monitors.
 
Unfortunatly no. I'm at work right now. I anted to post while I was at his house last night, but, unfortunalty, I couldn't get internet acess.
 
I was not on the phone with the cable company. they were having him do an ipconfig /all and reading the information back to them, so I would have to assume so. Stumped, right? :)
 
Pretty much...[cry] Can they offer him some alternate DNS servers? It just seems that having to reload is overkill... I would try uninstalling MSN, AOL, and all that crap first. Then remove TCP/IP and add it back in. If that doesn't work, do an install over itself. Instead of a clean install, choose upgrade... That should correct anything wrong with Windows, and he will not lose any programs or settings.... If that doesn't work.. [cannon]

Thanks,

Matt Wray
MCSE, MCSA, MCP, CCNA

 
Cable internet settings are pretty much "automatic". In Properties for TCP/IP Address; "Obtain IP Address(and DNS) Automatically" can be checked. Sometimes it takes awhile for the "request" to go through the first time.

An alternate method, which works 99% of the time for me: Power off the cable modem, PC, and router. Check connections. Then restart all. Give it a few minutes off and a few after you power on again.

Also the network settings have to be identical on all PCs in a workgroup. It's possible the tech at your ISP might not have the resources to troubleshoot home networking, even if it is supported. Suggest: practicallynetworked.com or
Of course a reformat, now and then, well....

Above all let your cable co. know you're having connectivity issues, OK?
 
Is your friend running a firewall? Also, is IE trying to go out through his former MSN dial-up?
 
My friend did a system restore over the weekend and everything is working correctly again. He was quite a downloader of file sharing programs and "adult" software, so spyware probably messed the whole computer up. I did run an Adaware scan on it, but it didn't solve any problems. Anyway, thank you for everyone's help.

Chris
 
have you tried useing the ip address in your brauser instead of the name, e.g. translates to ?
If this works you have problems with the DNS. If it doesn't work your packets are not routed to the ISP.
Somehow it is not clear to me what does work and what doesn't!

Plinius
 
I've run into a very similar problem today as well on a Win2k Pro box...which I've never seen before...Im' thinking it had to do with grokster and all those other POS programs as well...

Checked IP settings...running internal DNS server...all other machines on network are fine.
Let just talk internally for now....I can ping all IP's...I can do reverse lookups no problem. I can even ping my own machine by name...but if I try a forward lookup using a FQDN its unknown host.

NSlookup says dns server not responding, even though I can ping it and it works fine on other machines. I removed all networking components and rebooted and still the same thing...

Tried using my external dns server and doing an nslookup against it and it still doesn't work...I have no idea wth she did to that machine, but an sfc /scannow and a sp3 re-install and its still not working correctly...

going to end up rebuilding it as it will be quicker...curious wth caused it though as ad-aware was not picking anything up either...
 
We never figured out what exactly went wrong on his computer, although I am pretty confident that a spyware/adware program is the culprit.

My resonsoning for the above is because running a previous release of ad-aware on another of my friend's computers actually took away her ability to access the Internet, because of DNS problems. After going to the Lavasoft website and doing some research, I found out that Ad-Aware identified the problem and corrected it in a new release. If I remember correctly, Ad-Aware was trying to restore an Internet setting in the resgistry that got modified by a piece of spyware/adware.

This goes to show you the implications of downloading programs that contain this type of software. Not only did it install in the background while she was installing what she thought was a free piece of software, but it also modified general settings on her computer that applied to a variety of other software, which I find especially invasive. True, there is the fine print that we should be reading when we install these free programs, but sometimes I feel like I have to hire a lawyer just to dig through all the information within these statements to make sure I'm not giving myself the shaft. These programs tread the murky waters between legitimate software and trojan horses.
 
Rumple,

Try repairing your Winsock service stacks. This likely would have repaired cywinnik's issue as well:
The AdAware early version 6 registry problem is repaired by this easily.

If you are having DNS issues as described, a corruption in the registry for the service aspects of TCP/IP are strongly suggested as the cause. Often a maintenance upgrade of your OS will not repair the problem, as a repair of the registry is not attempted during this process.

Next time try the utility linked above. I cannot gaurantee it will fix your particular problem, but it certainly cannot hurt.
 
I did manage to fix the problem after having a good nights sleep...I remembered seeing sahagent.exe and a 3 sec check confirmed it was that damn shop at home agent...which corrupts the LSP...using LSPFix I was able to get the machine running in about 30 sec...man I should have had a nap while I was over there...lol
 
>>which corrupts the LSP...using LSPFix...<<

Huh?! I am having similar problems with one (and only one) computer on our network. I can successfully ping the wireless access point, the router, the IP assigned to our DSL connection and the DNS IP's identified by our ISP. If I try to ping our ISP (idcomm.com), however, I get an unknown host error. Pinging anything by name rather than IP gives me the error.

What is the LSP, and where can I find LSPFix? The user of the computer in question uses AOL. Could that have messed up his settings?
 
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