zone name for a reverse lookup zone

[Mark.Andrews at nominum.com]

> 
> At 10:50 AM +0000 5/11/01, syn uw wrote:
> 
> >  I am wondering what name I have to use for my reverse lookup zone name. I
> >  have the following network address 195.45.43.72/29 and currently as zone
> >  name I use: 43.45.195.in-addr.arpa, is that correct ? Or should I use
> >  72.43.45.195.in-addr.arpa ? Or doesn't it have any importance ?
> 
> 	The name of the zone file is irrelevant.  You could call it 
> SlartyBartFast and it wouldn't make a single bit of difference.  No 
> one outside of your machine will ever see that filename.
> 
> 	What is important is the fact that you tell BIND what the file 
> contains, so that it can properly fill in the blanks.  The label used 
> in the "zone" definition in the /etc/named.conf file is how BIND 
> determines what the origin (e.g., "@") will be defined to be.
> 
> 
> 	That said, to make your life in the future easier, and to make it 
> easier for someone else to come in and help you with domain 
> administration, it does make sense to apply certain rules to the 
> filenames you use.  Towards that end, using a name such as 
> 72.43.45.195.in-addr.arpa would probably make more sense.  You could 
> also specify the ending fourth octet, and call it 
> 72-80.43.45.195.in-addr.arpa.
> 

	What Brad failed to mention is that your ISP will need to
	setup a series of CNAME records that point into this zone
	from the 43.45.195.in-addr.arpa zone to allow the reverse
	resolution to work.  This need to be co-ordinated with your
	ISP.  You should also secondary this zone so that local
	lookups will work if outside link is down.

	This is all known as "Classless IN-ADDR.ARPA Delegation",
	see RFC2317

	zone "43.45.195.in-addr.arpa" {
		type slave;
		file "43.45.195.in-addr.arpa";
		masters { 192.106.1.1; };
	};

	zone "72-80.43.45.195.in-addr.arpa" {
		type master;
		file "72-80.43.45.195.in-addr.arpa";
	};

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