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DNS --> What exactly is reverse lookup Zones

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Hareth

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Jun 17, 2004, 10:56:40 AM6/17/04
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I know the definition o f Rev ookup zones, I even successfully set it up....

But with or without it, I have no idea what difference it made. What is the
the real point of Rlookup & and is it commoly used...


Herb Martin

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Jun 17, 2004, 11:13:50 AM6/17/04
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"Hareth" <abih...@hotmail.com> wrote in message
news:eeF30pHV...@tk2msftngp13.phx.gbl...

> I know the definition o f Rev ookup zones, I even successfully set it
up....
>
> But with or without it, I have no idea what difference it made. What is
the
> the real point of Rlookup

Not much.

> & and is it commoly used...

Sometimes.

Most people don't need it -- why did you set it up?

Sometimes it is necessary to achieve pseudo-security features.

--
Herb Martin


>
>


jjd...@nospamoptonline.net

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Jun 17, 2004, 1:27:34 PM6/17/04
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its actually becoming more necessary every day. aol for instance wont allow
incoming mail anymore unless they can successfully do a reverse lookup on
the mail server that sent the mail.... this helps to prevent spammers. so
yes, you should make it a habit to configure a reverse lookup zone


"Herb Martin" <ne...@LearnQuick.com> wrote in message
news:utoV$5HVEH...@TK2MSFTNGP09.phx.gbl...

Herb Martin

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Jun 17, 2004, 4:00:20 PM6/17/04
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<jjd...@NOSPAMoptonline.net> wrote in message
news:awkAc.23925$0b.94...@news4.srv.hcvlny.cv.net...

> its actually becoming more necessary every day. aol for instance wont
allow
> incoming mail anymore unless they can successfully do a reverse lookup on
> the mail server that sent the mail.... this helps to prevent spammers. so
> yes, you should make it a habit to configure a reverse lookup zone
>

But things like this are only likely to be true for the
PUBLIC reverse zones, and in general those are
maintained by the ISPs or NAPs.

He's asking about setting up his own reverse zones.

--
Herb Martin

Herb Martin

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Jun 17, 2004, 4:50:11 PM6/17/04
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"Phillip Windell" <@.> wrote in message
news:#tJ36uKV...@TK2MSFTNGP11.phx.gbl...

> "Herb Martin" <ne...@LearnQuick.com> wrote in message
> news:%23cTJubK...@TK2MSFTNGP11.phx.gbl...

> > But things like this are only likely to be true for the
> > PUBLIC reverse zones, and in general those are
> > maintained by the ISPs or NAPs.
> >
> > He's asking about setting up his own reverse zones.
>
> I don't have the previous posts, but if this is an AD DNS Server, I always
> take a "hands off" approach to them and only change/edit/add/remove what
is
> absolutely required for something to work properly and then just stay away
> from the thing. AD and DNS are so tightly intertangled together that all
> kinds of things can blow up in your face if you make it "angry".
>

You really don't have to be so skittish -- just a LITTLE more
understanding of DNS (and ADs use of it) will explain
what is safe and what is not.

They really are not "entangled" so much as AD is dependent
on Dynamic DNS. If you put DNS into AD that does constitute
some interdependence and it is an issue but that is pretty much the
only serious "entanglement."

However...
One mistake that is avoided by your approach is the person
who decides to enable "scavenging" and decrease the times
to minutes/hours (instead of weeks) and then manages to
"clean up the DC SRV records" while the DCs are out of
touch over a downed WAN line etc.


--
Herb Martin


> --
>
> Phillip Windell [MCP, MVP, CCNA]
> www.wandtv.com
>
>


Bill Grant

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Jun 18, 2004, 12:26:02 AM6/18/04
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To get back to the original question, a reverse lookup zone just enables
you to do a reverse lookup.That is, you can put in the IP address and get
out the machine name. A zone file is just a simple list, not a database. The
normal zone has the name listed first, and the query returns the IP. The
reverse zone has the IP first, and a query returns the name.

If you run any apps which require reverse lookups, they will fail if
you do not have a reverse lookup zone for the subnet.

"Herb Martin" <ne...@LearnQuick.com> wrote in message

news:#rxll3KV...@TK2MSFTNGP09.phx.gbl...

Jonathan de Boyne Pollard

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Jun 19, 2004, 6:48:20 AM6/19/04
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HM> Sometimes it is necessary to achieve pseudo-security features.

j> its actually becoming more necessary every day. aol for instance
j> wont allow incoming mail anymore unless they can successfully do
j> a reverse lookup on the mail server that sent the mail....

That's what Herb was referring to as "pseudo-security".

<URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/dns-avoid-double-reverse.html>

j> this helps to prevent spammers.

No, it doesn't. And here we go with short-term flawed measures
from AOL again. Haven't we enough evidence from history that these
don't work, yet ?

<URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/smtp-anti-ubm-dont-work.html#SourceRouting>

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