"Empty zones" and BIND 9.4

[Clenna Lumina]

Mark Andrews wrote:
>> For the loopback subnet reverse zone, if you want to create a PTR
>> record for each possible IP, use a wildcard. So instead of this from
>> Mark's example:
>>
>> 1.0.0 PTR localhost.
>>
>> use this:
>>
>> *     PTR localhost.
>>
>> Chris Buxton
>> Men & Mice
>
> Normally you only need "1.0.0 PTR localhost." as that
> is usually the only address in use.
>
> If you don't use it then you don't need a PTR.  If you do
> use it but forget the PTR then you want to stop the query
> leaking so that why the zone is 127.IN-ADDR.ARPA and not
> 1.0.0.127.IN-ADDR.ARPA, 0.0.127.IN-ADDR.ARPA or 0.127.IN-ADDR.ARPA.
> NXDOMAIN will be returned if there is no PTR record.

Maye I'm confused, but why is it 0.0.127.IN-ADDR.ARPA cannot be used? 
Why/how would that cause "query leaking" (and what is that exactly?)

I guess I jsut want to understand the logic & reasoning behind all this.

> Additionally the PTR from the wildcard will be rejected by
> may applications / libraries as there is not a corresponding
> A record.

Wouldn't it just map ever IP that starts with 127. to localhost? How 
would that break anything? Looking up, say, 127.0.0.21 would yield 
localhost, would it not? Sorry, I just don't see how this could be a 
problem.

-- 
CL

> I DO NOT recommend adding all the possible A records in this
> space.  It will only cause applications to break.
>
> Mark
>
>> On Jun 18, 2007, at 7:33 AM, Mark Andrews wrote:
>>
>>>
>>>> Hi all,
>>>>
>>>> There was big discussion about empty-zones feature in BIND >= 9.4
>>>> on Red
>>>> Hat's bugzilla. We have found two problems around this.
>>>>
>>>> - RFC 3330 says that loopback could be 127/8. Does anybody here
>>>> know how
>>>> configure 127.in-addr.arpa. zone as described in RFC? $GENERATE
>>>> directive isn't sufficient for solve this problem.
>>>
>>> Why would one want to use $GENERATE.
>>>
>>> zone "127.IN-ADDR.ARPA" {
>>> };
>>>
>>> @ SOA ..
>>> @ NS ..
>>> 1.0.0 PTR localhost.
>>>
>>>> - RFC 2181, section 7.3 tells about MNAME record in SOA. It's name
>>>> of primary server. All empty zones returns name of zone instead
>>>> primary nameserver (could be "localhost.")
>>>
>>> No.  It's the name of the primary (only) nameserver.  It just
>>> happens to be the name of the zone as well.  The zone names
>>> are all legal hostnames.
>>>
>>> draft-ietf-dnsop-default-local-zones-02.txt
>>>
>>> There are also named.conf options to change what is returned.
>>>
>>>> Thanks for any hints,
>>>> Adam
>>> --
>>> Mark Andrews, ISC
>>> 1 Seymour St., Dundas Valley, NSW 2117, Australia
>>> PHONE: +61 2 9871 4742                 INTERNET:
>>> Mark_Andrews at isc.org
>>>
>>>
>>
>>
> --
> Mark Andrews, ISC
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org