Aaron (ireland) wrote:
> "Kevin D. Goodknecht Sr. [MVP]" wrote:
>
>> Aaron (ireland) wrote:
>>> Hi Kevin,
>>>
>>> It was advised that we use dhcp to provide dns settings such as the
>>> external dns. I never understood why they had us provide client's
>>> with external dns when we use a proxy server. Maybe the installation
>>> of a new firewall etc.. will resolve this issue. Then I can remove
>>> external dns. See some clients access pop3 mail from external
>>> server's and without having external dns entries the clients are
>>> unable to recieve mail.
>>
>> POP3 mail clients such as OE and Outlook will use the DNS in the
>> client IPConfig for resolution unless it too is using a POP3 proxy,
>> in which case the proxy resolves the POP3 server's name.
>> If you use a Proxy, the web browser will get its DNS resolution from
>> the Proxy server, the only sites that will use the DNS in the
>> client's IPConfig are the sites that are configured to bypass the
>> Proxy server.
>>
>> Have you tried nslookup against the internal DNS to resolve the POP3
>> server's name?
> Results;
> Microsoft Windows XP [Version 5.1.2600]
> (C) Copyright 1985-2001 Microsoft Corp.
>
> C:\Documents and Settings\username>nslookup mail.company.ie
> *** Can't find server name for address 10.0.0.1: Non-existent domain

The above "***Can't find server name for address 10.0.0.2: Non-existent
domain" is not really an error, that is nslookup doing a reverse lookup on
the 10.0.0.1 DNS server IP address. If you will create a reverse lookup zone
and PTR for the IP this message will go away.

> Server: dns1.cwm.dublin.isp.net
> Address: xxx.xx.xxx.xxx

The above tells me that you have your ISP's DNS in TCP/IP properties, and
like the DNS Client service, nslookup will "Stick" to the DNS server that
replies. It dows not tell me that the internal DNS cannot resolve external
names. You need to remove the ISP's DNS from the TCP/IP settings and use
this command: nslookup mail.company.ie. 10.0.0.1


>
> I presume that they are the same as they reside on the same box. I
> used something like company.local for internal domain and company.ie
> for public domain. To answer your question yes I think they both have
> the same name.

How could they be the same name when the internal domain is company.local
and the public name company.ie?
What do you mean by they are on the same box?


Where is the mail server located?
It is VERY important that all internal clients use only the SBS IP
(10.0.0.1) for DNS only. You cannot allow an ISP DNS in TCP/IP properties on
ANY member of an AD domain, in any position. Then we can work on getting the
internal DNS server resolving internet names if it cannot.

825036 - Best practices for DNS client settings in Windows 2000 Server and
in Windows Server 2003
http://support.microsoft.com/default...825036&sd=RMVP

323380 - HOW TO: Configure DNS for Internet Access in Windows Server 2003
http://support.microsoft.com/default...323380&sd=RMVP

828263 - DNS query responses do not travel through a firewall in Windows
Server 2003:
http://support.microsoft.com/default...828263&sd=RMVP


--
Best regards,
Kevin D. Goodknecht Sr. [MVP]
Hope This s
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