This page is meant to describe the syntax for "Classless" subnets under BIND 8.2.3. If you're trying to upgrade from 8.2.2, banging your head against CNAME and other data (invalid) or CNAME and OTHER data error syslog errors, can't get those pesky PTR records straight for your "Classless" subnets, here's a full, functional example.

You should be able to set this up on an isolated network, work out any issues relative to your specific requirements.

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File: named.conf (partial): zone "test.com" { type master; file "named.test.com"; }; zone "4.168.192.in-addr.arpa" { type master; file "4.168.192.in-addr.arpa"; };

This example uses only a single domainname, test.com. Classless subnetting concerns numbered space. Named domains are not strictly tied to numbered space. Extend the example to suit your requirements. Most commonly: named.conf: zone "testA.com" file: named.testA.com named.conf: zone "testB.com" file: named.testA.com named.conf: zone "testC.com" file: named.testA.com As an alternate example, you might have delegated to you for use as a single named domain, test.com: a.b.111.0 /25 a.b.111.128 /25 a.b.112.0 /25 c.d.160.192 /26 You'd have only a single zone "test.com" in named.conf, but three (or perhaps four) numbered zones specified in named.conf. There are other applcations of Classless subnetting as well.

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File named.soa:

@ IN SOA	ns.test.com.	Postmaster.test.com. (
	2001013112	; yyyymmddn
	3600	; Refresh every hour
	900	; Retry 15 min
	3600000	; Expire after 1000 hours
	360000 )	; ttl of 100 hours
@ IN NS	ns.test.com.

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File 4.168.192.in-addr.arpa:

The meat of the problem is that ALL the CNAMEs for all of 4.168.192.in-addr.arpa. have to come first. Then the PTR records for the "Classless" subnets, with each Classless subnet anchored by an $ORIGIN.

$INCLUDE named.soa
$ORIGIN 4.168.192.in-addr.arpa.
$GENERATE 1-127 $ CNAME $.0/25.4.168.192.in-addr.arpa.
$GENERATE 129-254 $ CNAME $.128/25.4.168.192.in-addr.arpa.
$ORIGIN 0/25.4.168.192.in-addr.arpa.
1	IN PTR one.test.com.
2	IN PTR two.test.com.
3	IN PTR tre.test.com.
$ORIGIN 128/25.4.168.192.in-addr.arpa.
129	IN PTR for.test.com.
130	IN PTR fif.test.com.
131	IN PTR six.test.com.

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File: named.test.com:

$INCLUDE	named.soa
localhost	IN A 127.0.0.1
one	IN A 192.168.4.1
two	IN A 192.168.4.2
tre	IN A 192.168.4.3
for	IN A 192.168.4.129
fif	IN A 192.168.4.130
six	IN A 192.168.4.131

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