Re: Strange DNS problem

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From: Tom B (tbokman_at_hotmail.com)
Date: 09/06/04 

Date: Sun, 5 Sep 2004 17:46:07 -0700

This problem is on a friend's PC. I took my laptop to my
friend's home and removed his PC and connected my laptop
to his DSL line. I made sure my all my TCP/IP properties
were set the same as my friend's PC. With my laptop
connected I could get to all web sites by name and ping
both IP addresses AND DNS names. Therefore I'm sure the
ISPs DNS servers are working correctly.

The node type on both my laptop and his PC
shows "Unknown". I checked his hosts file in
C:\WINDOWS\system32\drivers\etc\ and is has the original
127.0.0.1 localhost AND on the line below I added the
following:

216.109.112.135 yahoo.com

The only other hosts file is in the i386 folder. When I
ping yahoo.com it reports "ping request could not find
host yahoo.com" so it looks like DNS is not functioning
on this PC.

I thought this might be an spyware problem so I installed
Adaware on his PC and it found a lot of stuff which I had
it fix but it did not fix the DNS problem. Is it possible
that some how DNS has been turned-off or disabled on this
PC? Also how can I be sure the DNS cache is working? I
did IPCONFIG /flushdns and got "Successfully flushed the
DNS Resolver Cache" but it did not fix the problem.

Thanks for your help.

>-----Original Message-----
>On Sun, 5 Sep 2004 15:02:49 -0700, "Tom B"
<tbokman@hotmail.com> wrote:
>
>>I have a winXP home version with a very strange
problem.
>>When I use Internet Explorer, I cannot connect to any
web
>>sites by name (eg. yahoo.com) but I can connect using
the
>>IP address for the site (eg. 216.109.112.135). This
>>indicates a DNS problem.
>>
>>I ran IPCONFIG /ALL to get the IP address of the DNS
>>servers. I can ping both DNS servers IP address. But
when
>>I ping by name it reports "ping request could not find
>>host yahoo.com". I tried adding "216.109.112.135
>>yahoo.com" to the hosts file but ping still reports
could
>>not find host.
>>
>>Also when I ran NETSTAT -a the local address column
shows
>>blanks instead of the computer name and port. But
>>NETSTAT -an does show the IP address and port number.
>>
>>Something with DNS is really broken on this PC but I'm
>>not sure how to fix it. Any ideas? Don't really want to
>>wipe the disk and re-install the OS. Thank in advance
for
>>your help.
>
>Tom,
>
>What Node Type shows in IPConfig?
>
>Search your entire system drive, including hidden and
system folders, for file
>"hosts". There is one legit copy, in C:\WINDOWS\system32
\drivers\etc\. The
>others are possibly bogus, and part (but just part) of
the problem. Examine the
>contents of each copy found, using Notepad. (HINT:
Scroll to the end of each
>Hosts file, by hitting Ctrl-End, then back up to the
top, page by page, before
>deciding that the file is empty. Look out for blank
lines at the beginning and
>end of the file, after localhost, placed there by an
exploit!)
>
>A hosts / lmhosts entry with your ip address, and no
name, would make your
>computer name show as blanks in "netstat -a".
Typically, local names (on your
>LAN) are resolved by DHCP / NetBIOS / WINS (or
lmhosts). Internet host names
>are resolved by DNS (or hosts), or you might have a dns
cache on your computer.
>
><http://support.microsoft.com/default.aspx?scid=kb;en-
us;160177>
>
>Cheers,
>Chuck
>Paranoia comes from experience - and is not necessarily
a bad thing.
>.
>

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