a bit of theory about PTR records requested

[Steve Lee]

what is the difference between  A and the PTR  ?
i can see that one does the opposite of of the other
but what does the A and the PTR stand for?

thanks.

On Wed, 29 Mar 2000, Gregg Rosenberg wrote:

> If we are talking external address space.  Any address not actually being 
> used for accessing a machine on the inside or any address used for NAT is 
> given a generic name.  You definitely must have an external reverse for 
> authentication.
> 
> Here you could try a wild card PTR.  Although I don't like that method.  My 
> preference is to setup generic names that can be easily script or 
> spreadsheet generated for both the forward and reverse.
> 
> Forward:
> host-64-4-192-1 IN      A       64.4.192.1
> host-64-4-192-2 IN      A       64.4.192.2
> host-64-4-192-3 IN      A       64.4.192.3
> 
> Reverse:
> 64.4.192.1              IN      PTR     host-64-4-192-1.
> 64.4.192.2              IN      PTR     host-64-4-192-2.
> 64.4.192.3              IN      PTR     host-64-4-192-3.
> 
> You can make the names as simple or complex as you like.
> 
> 
> At 08:26 AM 03/29/2000, Martijn van Katwijk wrote:
> >At 15:44 29-3-00, Gregg Rosenberg wrote:
> >>With the address range you are showing, I will assume that we are looking 
> >>at an internal DNS for address space behind your firewall.
> >
> >No, i'm sorry, it was meant to be an example. Wrong example...
> >
> >I'm deleting a lot of PTR records now (one PTR per IP), so i'm happy. I 
> >know what to do.
> >
> >Thanks!
> >
> >
> >>There are slight performance advantages to setting up reverses.  If your 
> >>users are not connecting to any services on the inside that require 
> >>reverse authentication it likely does not matter.  I personally consider 
> >>it a good practice to do.  Depending on your environment there are 
> >>different ways to approach this.  If you are running a DHCP server with 
> >>statically assigned leases, you can dump your DHCP table into Excel (or 
> >>some other favorite spreadsheet tool) and use a macro to make the reverse 
> >>file.  You could write a script to convert your forward into a reverse 
> >>and run it each time you make a change.  (one may exist on the net, 
> >>although I don't personally no of it.  The other option might be to 
> >>consider using dynamic DNS with DHCP.  This is still a bit new and likely 
> >>will require patience and testing.  I hope these ideas are helpful.
> >>
> >>At 03:33 AM 03/29/2000, Martijn van Katwijk wrote:
> >>>Hi,
> >>>
> >>>I also have zones like this:
> >>>domain.com.     IN      A       192.168.1.60
> >>>www             IN      CNAME   domain.com.
> >>>
> >>>In fact I have quite a lot of these, all pointing to a single virtual 
> >>>name based webserver with only a few IP nrs assigned to it.
> >>>So I have a lot of A records to a single IP nr.
> >>>
> >>>Do I have to configure a PTR for each A record? Or is that meaningless.
> >>>
> >>>Thanks,
> >>>Martijn
> >>
> >>--
> >>Gregg Rosenberg -- N9NNO
> >>RICIS, Inc.
> >>gregg at ricis.com
> >>
> >>"Obstacles are those frightful things you see when you
> >>take your eyes off your goals."  Author unknown
> >>
> >>
> >
> >
> >Martijn van Katwijk
> >__________________________________________
> >AAA on Internet
> >http://www.aaa.nl/
> >info at aaa.nl
> >+31 342 418225 (Tel)
> >+31 342 423568 (Fax)
> >
> >
> >http://www.uwnaamhier.nl?
> >http://Registreer.uwDomein.nu!
> >
> >
> >
> 
> --
> Gregg Rosenberg -- N9NNO
> RICIS, Inc.
> gregg at ricis.com
> 
> "Obstacles are those frightful things you see when you
> take your eyes off your goals."  Author unknown
> 
> 
>