[rescue] DNS questions

[Paul Sladen]

On Mon, 22 Oct 2001, Michael S. Schiller wrote:

> I just got a block of 8 IPs from my ISP (after maybe 3 weeks of talking to
> almost everyone there), and I supposedly have full authority (reverse as well
> as forward) over them. My question is 2 fold: 1. How do I know if I really have
> authority over the reverse DNS & 2. If I do, is there an easy way to set it
> up? I've looked at the classless stuff, but I find it confusing. Thanks.

Righty... take one of the IPs in your block: say 192.168.24.7

  % dig -x 192.168.24.7 cname
  [...]
  7.24.168.192.in-addr.arpa. 3600 IN CNAME 7.0-7.24.168.192.in-addr.arpa.
  [...]
---------------------------------------------^^^

Check what naming scheme they have used to delegate it to you,  in this
case, they have CNAMEd the entries to entries that you serve under the:

  0-7.24.168.192.in-addr.arpa.

domain.  So, hopefully, looking up:

  % dig 0-7.24.168.192.in-addr.arpa. ns
  [...]
  0-7.24.168.192.in-addr.arpa. 3600 IN NS  ns0.you.com.
  0-7.24.168.192.in-addr.arpa. 3600 IN NS  ns1.you.com.
  [...]

will [hopefully] show your name servers;  so just make your name servers
serve up this domain:

$ORIGIN 0-7.24.168.192.in-addr.arpa.
$TTL 10800
SOA [...]
		IN NS	ns0.you.com.
		IN NS	ns1.you.com.
0		IN PTR	network.you.com.
1		IN PTR	gw.you.com.
2		IN PTR	foo.you.com.
3		IN PTR	bar.you.com.
4		IN PTR	baz.you.com.
7		IN PTR	broadcast.you.com.

Paul

PS.  Just noticed that the latest dig on this machine *doesn't* like looking
up non-numerics with `-x', and chokes on  `dig -x 1.2.3.40-47'. Debian box..!