staedtlerx wrote:
> Hello All,
>
> I thank you ahead of time if you read all this - I'm having a very
> strange network problem and someone recommended Wireshark for
> debugging it - and it's quite amazing! It's provided some insight but
> I am not that familiar with low-level TCP/IP stuff so I don't know
> what to make of it all. I was hoping someone could provide some more
> insight or any hints for further debugging.
>
> I am using a Sony Vaio Laptop with Windows XP SP2. It has internal
> WiFi, which works fine; Goes on the internet, etc. I'm sending this
> email with it right now. I have 4 other ways of connecting the laptop
> to the internet: 2 PCMCIA wifi cards and 2 wired ethernet connections.
> These 4 other connections all behave exactly the same: They *appear*
> to not have DNS (more on that later) and and they cannot access any
> remove server by hostname. They CAN access any remote server by IP
> address e.g. can browse to
http://74.125.45.100 but not
>
http://google.com. However, they CAN access remote server by name if I
> put an entry in my hosts file. This would lead most people to believe
> that my DNS is not working correctly. I also get "Ping request could
> not find host" when trying to ping a hostname. Again, would make you
> think DNS was not working. However, the problem is not that simple.
> All 5 connections have the same gateway, dns, etc - yet the internal
> wifi works and the 4 others don't. I've tried every sort of winsock
> reset, reinstalling, dns cache clearing, etc. I've tried driver
> upgrades, downgrades, etc. I've tried everything in safe mode. I've
> tried connecting my laptop to my cable modem directly and I've also
> tried through my Wifi router. The problem definitely lies within my
> Windows software - not hardware, router, firewall, or ISP. The monkey
> wrench is that I have the one internal wifi connection thats works!
>
> Now, more on the part about *appearing* not to have DNS: I figured
> something, somewhere, was messing with my DNS (lord knows why on only
> 4/5 connections). This is when I got Wireshark for some deeper
> insight. Snooping with Wireshark, I can see that hostnames actually DO
> resolve to their IP. I can see a response from my gateway with the IP
> address then I get an ICMP failure "Destination Unreachable":
>
> 192.168.0.2 -> 192.168.0.1 - DNS Standard query A
google.com