Silly question... child/parent setup

[phn at icke-reklam.ipsec.nu]

Jonathan Angliss <valcor at fluxnet.org> wrote:

> Hi All,

> This is probably a really silly question, but I cannot find any docs, or
> any books on this subject.  The book I did find (DNS & Bind) has a bit
> about setting up the parent, but nothing on setting up the child.  Here
> is the situation.  We have been assigned by our ISP a block of 5 IP
> addresses, and was curious about taking over the reverse lookup for those
> addresses, as well as hosting our domain on those addresses.  Doing the
> forward is easy, it's running, tested, and nearly ready to be set as the
> DNS for the domain.  The issue comes to reverse DNS for the block.  I've
> seen how the parent is setup, and it is fairly simple (in my mind
> anyway).  The question comes is how to setup the reverse for the 5
> addresses we have.  Could somebody give me any ideas (or examples)?

It is described in the book ( if you have version 4 of the book )

However a variant that i use to do for small numbers may be of
interest :

The ISP is probably doing reverse.Let him create 5 CNAMES, one for
each of your IP's ( assume you have 1 2 .. 5 is last digit, in the ISP
zonefile he will have :

@	SOA  (usual stuff)
	NS  (a number )

1	IN	CNAME	1.(your-domain.)
2	IN	CNAME	2.(your-domain.)
 etc
5	IN	CNAME	5.(your-domain)

As you see the cnames "points" into your normal forward-domain, which you
already have. You don't need to set up a separate file for the reverse,
instead you create in your forward zone :

@	SOA  ( usual stuff )
	IN NS	( at-least 2 namesevers, as usual)

	IN	MX 10 (your mailhost)

www	IN	A	x.y.z.1
mail	IN	A	x.y.z.2
etc
ftp	IN	A	x.y.z.5


( now comes the trick )
1	IN	PTR	www.(yourdomain).
2	IN	PTR	mail.(yourdomain).
erc
5	IN	PTR	ftp.(yourdomain).


This will work just fine since no hosts will ever be named to "only-digits"
thus no namecollsion will occur.



> Thanks
> Jonathan


-- 
Peter Håkanson         
        IPSec  Sverige      (At the Riverside of Gothenburg, home of Volvo)
           Sorry about my e-mail address, but i'm trying to keep spam out.
	   Remove "icke-reklam" and it works.