Delegate part of C-class according to RFC2317

[Mark.Andrews at nominum.com]

> One of our customers requested we'd delegate their part of a c-class to
> their dns according to the standard described in RFC2317.
> 
> The Setup:
> What I did was to "solve" (?) it like this:
> (In a file similar to xxx.xxx.xxx.db)

In your zone file for xxx.xxx.xxx.in-addr.arpa.

160-191	IN NS   ns.company.com.
160-191 IN NS   ns1.isp.com.
160-191 IN NS   ns2.isp.com.

161    IN CNAME        161.160-191.xxx.xxx.xxx.in-addr.arpa.
162    IN CNAME        162.160-191.xxx.xxx.xxx.in-addr.arpa.
---SNIP---
191    IN CNAME        191.160-191.xxx.xxx.xxx.in-addr.arpa.



In 160-191.xxx.xxx.xxx.db on ns.company.com.  Your servers are
slaves.

; Implicit "$ORIGIN 160-191.xxx.xxx.xxx.in-addr.arpa." from named.conf.
@	IN SOA   ns.company.com. ...
@	IN NS   ns.company.com.
@	IN NS   ns1.isp.com.
@	IN NS   ns2.isp.com.
 
;160    IN PTR	RESERVED
;161    IN PTR	host1.company.com.
 ---SNIP---
;190    IN PTR  host30.company.com.
;191    IN PTR  RESERVED

Note also you should be letting your customers transfer
xxx.xxx.xxx.in-addr.arpa as they need to have a local
copy of this zone if their link goes down. They should
be a stealth slave (not listed in NS records) for
xxx.xxx.xxx.in-addr.arpa.  Add them to the also-notify list.

The ns1.isp.com and ns2.isp.com should be the same servers as
xxx.xxx.xxx.in-addr.arpa is delegated to.

Mark
--
Mark Andrews, Nominum Inc.
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at nominum.com