Re: Reverse DNS?

[Will Trillich <will@serensoft.com>]

On Tue, Aug 17 at 09:31AM -0300, Leandro Guimaraens Faria Corsetti Dutra wrote:
> Em Tue, 17 Aug 2004 10:50:06 +0200, Bill Wohler escreveu:
> > what questions do I need to ask my
> > sysadmin to get my hostname/IP address into the DNS in my network at
> > work? An apt-cache search on "reverse DNS" didn't pick anything up

for the FULL answer check "dns and bind" from o'reilly. you can
google for it online and read it there, too. it talks about bind
versions 4 and 8, and 9 is similar enough to 8 that you should be
able to interpolate.



short answer -- presuming that you have a static ip address and
that you registered a domain name at an official registrar:

- when you registered your domain, you selected some nameservers
  for it -- those DNS servers need to have resource records
  pointing to the IP address you're using

$TTL 1W
@	IN	SOA	your.domain.name. root.your.domain.name. (
			200408017
			24H
			2H
			21D
			2D )
;
			NS		nameserver.out.there.
			NS		another.name.server.
;					mail.your.domain.name.
			MX	10	mail
;		address for zone your.domain.name.
		A		1.2.3.4
;
; address for mail.your.domain.name.
mail	A		1.2.3.4
; address for www.your.domain.name.
www 	A		2.4.6.8
;
dox		CNAME		www

	the first "A" is the address for the zone; the second is the
	address for host mail.your.domain.name -- it happens to be at
	the same address as the zone in this example. the third is
	the address for the webserver www.your.domain.name and it's
	at a totally different address. and "dox" is declared to be a
	synonym for "www", so wherever www points to, dox does too.

- for reverse mapping, you need to get whoever's in charge of the
  in-addr.arpa range of addresses you're in, to set that up for
  you:

	whois 4.3.2.1.in-addr.arpa
	whois 3.2.1.in-addr.arpa
	whois 2.1.in-addr.arpa

(your ip address, in reverse order -- and pare off the leading
chunk until you find someone in charge)

note that in the example above i used address 1.2.3.4 for the
domain and the mail server, but 2.4.6.8 for the web server (and
the dox synonym) so the latter would be attended to at
8.6.4.2.in-addr.arpa (or 6.4.2.in-addr.arpa, etc).

they'll need to set up PTRs such as

	; e.g. zone 3.2.1.in-addr.arpa
	4	PTR	your.domain.name.

	; e.g. zone 2.1.in-addr.arpa
	4.3	PTR	your.domain.name.

but to get them to do so you need to make their lives as easy as
possible by sending them the precise strings to cut and paste --
after all, you're asking them to do you a favor.

-- 
I use Debian/GNU Linux version 3.0;
Linux boss 2.4.18-bf2.4 #1 Son Apr 14 09:53:28 CEST 2002 i586 unknown
 
DEBIAN NEWBIE TIP #1 from Will Trillich <will@serensoft.com>
:
Looking to use your Debian machine as a FIREWALL? No problem!
Try "apt-get install ipmasq"... After you've got your
/etc/network/interfaces file set up properly, ipmasq will save
you lots of work, setting up rudimentary firewall and routing
tables automatically. Shorewall is more powerful and a better
firewall than ipmasq, but ipmasq is a handy get-up-and-running
tool for newbies.

Also see http://newbieDoc.sourceForge.net/ ...