Re: Windows DNS and RBL Lookups

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From: Herb Martin (news_at_LearnQuick.com)
Date: 02/01/05 

Date: Mon, 31 Jan 2005 20:20:21 -0600

"KenM" <KenM@discussions.microsoft.com> wrote in message
news:7DADECD6-20EF-4C93-8AD7-90C089E15A51@microsoft.com...
> Hi Herb...
>
> Thanks for your response...To be honest, I am satisfied that it works
> without the forwarder. All of the lookups seem a bit quicker this way.
>
> I am curious though....I did try the
> "nslookup 2.0.0.127.bl.spamcop.net ISP.DNS.IP.ADDRESS"
> and it came back just fine and quick. How would I find the next DNS in
the
> chain?

You would probably have to know it --
that is go to the DNS server and see who
you have it forwarding to, or ask the ISP
if you have forgotten the appropriate
address. 

-- 
Herb Martin
>
> Thanks
>
> Ken
>
>
> "Herb Martin" wrote:
>
> > "KenM" <KenM@discussions.microsoft.com> wrote in message
> > news:D570DABF-3CD6-4DB2-9294-EABCF26F6330@microsoft.com...
> > > Well, Like I said, I am not an expert....
> > >
> > > It was my understanding when I set this up, that since I was only
using it
> > > for local hosts, that I should have it forward all other requests to
my
> > ISP
> > > DNS.
> >
> > That is perfectly fine IF the ISP DNS is reliable.
> >
> > > Are you suggesting that I remove the forwarder and just use root
hints?
> >
> > You method is perfect fine (better than this actually)
> > so I believe that he was suggesting you try it to see if
> > this changes the behavior -- that might be useful if the
> > ISP has an unreliable DNS server but it would not
> > be my first choice with a reputable ISP.
> >
> > How about we approach it systematically?  (Unless you
> > are satisfied that it now "works" from your other post...)
> >
> > You can test against each DNS server in the chain by
> > using NSLookup (ignore any initial report of being unable
> > to find the name of the SERVER, it's a bogus NSLookup
> > error.)
> >
> > nslookup www.Yahoo.com  YOUR.DNS.IP.ADDRESS
> > nslookup 2.0.0.127.bl.spamcop.net  ISP.DNS.IP.ADDRESS
> >
> > You might have to play around with the "timeout"  (-time=10)
> > so see if delaying for slow answers helps:
> >
> > nslookup -time=10 www.Yahoo.com  YOUR.DNS.IP.ADDRESS
> > nslookup -time=10 2.0.0.127.bl.spamcop.net  ISP.DNS.IP.ADDRESS
> >
> >
> > -- 
> > Herb Martin
> >
> >
> > "KenM" <KenM@discussions.microsoft.com> wrote in message
> > news:D570DABF-3CD6-4DB2-9294-EABCF26F6330@microsoft.com...
> > > Well, Like I said, I am not an expert....
> > >
> > > It was my understanding when I set this up, that since I was only
using it
> > > for local hosts, that I should have it forward all other requests to
my
> > ISP
> > > DNS.
> > >
> > > Are you suggesting that I remove the forwarder and just use root
hints?
> > >
> > >
> > >
> > > "neo [mvp outlook]" wrote:
> > >
> > > > Out of curiosity, why do you use forward lookups?  Why not just let
the
> > > > server go straight to the internet and see if you get the same
results.
> > > >
> > > > "KenM" <KenM@discussions.microsoft.com> wrote in message
> > > > news:AB31DFC0-4134-4710-8D5B-A64D8F56960D@microsoft.com...
> > > > >I will start by admitting that I am by no means an expert in DNS.
> > > > >
> > > > > I have a novell network, but happen to have an ISA 2004 Firewall
on a
> > > > > windows server 2003 server with DNS running.  I have about 20
local
> > hosts
> > > > > entered and am basically just using it to prevent creating hosts
files
> > for
> > > > > everyone.  I have setup my ISPs DNS as a forwarder to handle all
of
> > the
> > > > > external domain lookups.
> > > > >
> > > > > In nslookup, it seems to work just fine as far as resolving names,
but
> > I
> > > > > can't seem to get it to work correctly to do RBL lookups.  For
> > example,
> > > > > 2.0.0.127.bl.spamcop.net should come back as 127.0.0.2, but
instead,
> > my
> > > > > DNS
> > > > > just times out.  If I set my ISPs DNS as the name server, the RBL
> > resolves
> > > > > back to 127.0.0.2 just fine.  The same appears to be true from my
> > email
> > > > > gateway.  When it is set to use the ISP DNS for resolution, the
RBL
> > > > > lookups
> > > > > work good, but when the local DNS is used, the lookups are slow
and
> > fail.
> > > > >
> > > > > I have been searching the internet for info on what might be the
cause
> > of
> > > > > this, but so far, all I have found is that "if it doesn't work,
there
> > is
> > > > > something configured wrong in my DNS server", but no clue as to
what
> > it
> > > > > might
> > > > > be.
> > > > >
> > > > > If anyone can help get me pointed in the right direction it would
be
> > > > > greatly
> > > > > appreciated!!
> > > > >
> > > > > Thanks.
> > > > >
> > > > > Ken
> > > >
> > > >
> > > >
> >
> >
> >

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