reverse lookup dns zone

Hi All:

I'm having a hard time getting a clear answer on the following.

I have a Windows 2003 Active Directory with about 300 machines, all
belonging to a single domain. If its relevant, I do run a RAS server
and exchange server and otherwise, pretty standard stuff.

In this type of environment, in my DNS, do I need a reverse lookup
zone?

I believe I understand if I don't have one that I won't, as an admin,
be able to do nslookup <ip address> and get a computer name back.
Would this also mean that tracert wouldn't be able to resolve an
address to a name?

I know that the reverse lookup to the mail server must be valid as
this is used as a spam prevention technique.

But outside of this, in this basically flat network topology, do I
need a lookup zone?

Any info or advice or what having the reverse lookup gets me in this
environment is much appreciated!

Thanks!
Drew

ZiadKChafi
Thu Mar 27 02:13:01 PDT 2008

Hi Drew,
It is not obligatory to have a reverse lookup zone on your local network,
having one will enable you to to convert an IP address to a DNS name using
nslookup or PING -a followed by the ip address ONLY ON YOUR LOCAL NETWORK,
this has no effect on internet IPs, Exchange, or RAS servers, you can still
use nslookup to find the DNS name of a public PTR record, exchange can still
do its own revers lookups on the internet. So it is not obligatory to add the
reverse lookup zone on the DNS, although it can be helpful sometimes and will
not cost you anything.

Ziad K. Chafi

"Drew" wrote:

>
> Hi All:
>
> I'm having a hard time getting a clear answer on the following.
>
> I have a Windows 2003 Active Directory with about 300 machines, all
> belonging to a single domain. If its relevant, I do run a RAS server
> and exchange server and otherwise, pretty standard stuff.
>
> In this type of environment, in my DNS, do I need a reverse lookup
> zone?
>
> I believe I understand if I don't have one that I won't, as an admin,
> be able to do nslookup <ip address> and get a computer name back.
> Would this also mean that tracert wouldn't be able to resolve an
> address to a name?
>
> I know that the reverse lookup to the mail server must be valid as
> this is used as a spam prevention technique.
>
> But outside of this, in this basically flat network topology, do I
> need a lookup zone?
>
> Any info or advice or what having the reverse lookup gets me in this
> environment is much appreciated!
>
> Thanks!
> Drew
>