Re: DNS resolution not working (Win2k Pro)

From: Gerhard Fiedler (lists_at_connectionbrazil.com)
Date: 12/10/04 

Date: Fri, 10 Dec 2004 11:50:47 -0200

First off, thank you all very much for your help. That's a not so common
experience in newsgroups these days... :)

It seems I created some confusion not describing the complete situation.
Here it is:

- I am off-site, using my own ISP to connect through pcAnywhere to one
computer on a client's internal network.
- This one computer is an FTP server. All other computers on that network
are normal office PCs.
- The client's internal network is connected to the Internet through the
client's ISP.
- The ISP has some firewall running, but opened the ports I need to connect
to that one computer (and some others we need for that machine).
- The two DNS servers that don't work are the ones that my client has
received from their ISP.
- They are also the ones they see in the ipconfig output of their office
PCs (which work fine).
- But I haven't yet seen an actual copy of ipconfig or nslookup output. So
far they just confirmed that the numbers were the ones. This is what I'm
waiting for now.
- In the meantime, I have set up that one machine to use the DNS servers of
my own ISP (which is different from my client's ISP). It works fine with
these DNS servers. I think that's ok, as long as it is a temporary
solution. After all, they only get used very rarely (that machine is not
typically used for browsing, only when I download updates etc.)

Hope this clarifies some of the confusion I created.

At this point, I'm waiting for the copies of the outputs of a few commands
run on their normal PCs to see what exactly these PCs do, and whether they
in fact are using these two DNS servers that don't work -- not from that
machine, not from here, and not from a few other places (as you were nice
enough to check also).

I guess if in fact the other office PCs use these two DNS servers and they
work there, we have some kind of firewall problem with my client's ISP.

If the office PCs use other DNS servers, then the whole thing was a
miscommunication from my client's ISP to my client and from my client to
me.

See also some inline comments below.

Thanks,
Gerhard

Herb Martin wrote:

> You need a reliable DNS server (set) even if you have to install one
> yourself.

I know. And I intend to get one from my client's ISP :) I think it's their
responsibility to provide that.

>> I know... no offense taken :) But when I use the DNS servers of my own ISP
>> (for example 200.174.144.14), it all works -- the nslookup works, and
>> normal Internet access and DNS resolution too if I add it to the DNS
>> servers in the connection configuration. So I guess the firewall is not a
>> problem.
>
> What do you mean "of your own ISP"?

I hope that the above has cleared that up. I am off-site and using a
different ISP than my client, where the one computer with the DNS server
problem is located.

> Why aren't you using YOUR ISP DNS?

I think I wrote that I'm using my ISP's DNS server :) And the whole
problem is that the client's DNS servers (or what I currently have reason
to believe what they are) don't work from that one computer. So I added
temporarily the DNS servers of my own ISP to the list of DNS servers on
that problematic machine, just to get it working for now.

>> It looks like something's wrong with the DNS server addresses they got
>> from their ISP.

> Or the DNS servers are firewall -- or set so the clients are
> considered "foreign" and therefore not serviced.

Yes. I'm waiting for some feedback about other machines on the network to
see what their exact setup is.

> nslookup is a pretty funky tool (e.g., it gives bogus errors if their is
> no reverse-PTR record for the DNS server) but it has the advantage
> of being available on all NT-class machines that have IP.

Thanks for that info. I've always thought that networking is some kind of a
black art... :)

Relevant Pages

  • Re: Cannot Surf Internet, but I can Ping
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    (Ubuntu)
  • Re: DNS resolution not working (Win2k Pro)
    ... > client's ISP. ... I have set up that one machine to use the DNS servers ... > I guess if in fact the other office PCs use these two DNS servers and they ... > miscommunication from my client's ISP to my client and from my client to ...
    (microsoft.public.win2000.dns)
  • Re: Discover Outgoing IP address
    ... > believe) can only mean that your ISP puts it's customers inside a "Network ... >> but my router reports the range.81.105.x.x range ... >>> It would most likely mean that your WAN address that the router sees is ... If your current dns servers don't support dynamic update, ...
    (microsoft.public.windows.server.sbs)
  • Re: MX Record Question
    ... Is if my ISP configured to redirect some services like FTP, ... > Somewhere you must have a public IP assigned to your internet connection with SBS where a second nic to the internet connection or a single nic connected to a router ... > valid domain that I set when I run CEICW. ... >> All DNS records regarding your valid domain should probably be on your ISPs two authoritative DNS servers ...
    (microsoft.public.windows.server.sbs)
  • Re: My Linksys WRT54GS router is losing its DNS configuration ...
    ... Are you sure your ISP juggles DNS servers? ... I looked at the router status page and saw the 2 DNS IP ... Are you sure that you're using DHCP and not PPPoE or PPPoA? ...
    (alt.internet.wireless)