[Dnsmasq-discuss] PTR records with auth-zone and auth-server

[Craig McQueen]

On 04/04/14 07:28, Simon Kelley wrote:
> On 03/04/14 08:22, Craig McQueen wrote:
>> * No custom PTR records can be defined with ptr-record.
>
> That's behaving as documented, --ptr-record doesn't appear in the list
> of data included in an authoritative zone given in the AUTHORITATIVE
> CONFIGURATION section of the man page. The reason is, I think, that
> PTR-records can have any name, not just w.x.y.x.in-addr.arpa. It's
> therefore difficult to use the subnet(s) associated with an auth-zone to
> filter them. It would be possible to filter on the name using the domain
> associated with an auth zone, and filter w.x.y.x.in-addr.arpa on the
> subnet. That's quite complex to understand/document/use.

DNS-SD (RFC 6763) makes use of PTR records that end in the domain name. 
E.g. ending in example.com.:

_http._tcp.example.com.
lb._dns-sd._udp.example.com.

DNS-SD also makes use of PTR records that end in the reverse mapping 
name of the network address of the subnet. E.g. for subnet 
192.168.5.0/24, some PTR records ending in 0.5.168.192.in-addr.arpa.:

b._dns-sd._udp.0.5.168.192.in-addr.arpa.
lb._dns-sd._udp.0.5.168.192.in-addr.arpa.

It would be good to allow ptr-record options that match either of these 
cases.

The first case (ending in example.com.) should be straight-forward. The 
reverse case should also be okay, unless I'm overlooking some 
complication. I haven't looked into the IPv6 case.

DNS-SD also uses SRV and TXT records, ending in .example.com.

Thanks,
Craig McQueen