comcast ipv6 PTR

Tue Oct 15 08:32:02 UTC 2013

On 10/15/13 7:54 AM, "Mark Andrews" <marka at isc.org> wrote:

>
>In message <20131015024711.55297.qmail at joyce.lan>, "John Levine" writes:
>> >Is there any reason other than email where clients might demand RDNS?
>> 
>> There's a few other protocols that want rDNS on the servers.  IRC maybe.
>> 
>> Doing rDNS on random hosts in IPv6 would be very hard.  Servers are
>> configured with static addresses which you can put in the DNS and
>> rDNS, but normal user machines do SLAAC where the low 64 bits of the
>> address are quasi-random.  To get any sort of DNS you'd need for the
>> routers to watch when new hosts come on line and somehow tell the
>> relevant DNS servers what hosts need names.
>> 
>> This would be a lot of work, so nobody does it.
>
>Actually you just need to *let* the hosts update their own ptr
>records using UPDATE.

Cool. How do I tell a residential device what name server they should send
updates to?
Remember that the ISP uses DHCPv6 or PPPoE or TR-069 to send configuration
information to the CPE, which sends DHCPv6 or RA to hosts.  "Hosts" may be
computers, tablets, game consoles, phones, TVs, or other.

>
>People keep saying the PTR records don't mean anything yet still
>demand really strong authentication for updates of PTR records.
>TCP is more than a strong enough authenticator to support update
>from self.

Dynamic DNS uses TCP?  I didn't realize that.

>
>You can even delegate the reverse zone when doing or just after a PD.

To a home router?  How do you tell the home router that it is now
authoritative for the reverse zone?

>
>* Extend DHCPv6 to support delegations (NS or DNAME) relayed via
>  the DHCP server as part of the PD.  NS records would result in a
>  temporarially lame delegation until the zone is configured in the
>  nameserver.

Let me know when you need me to express support for your draft being
adopted by dhc WG.
Until that feature is implemented, it is of limited operational utility.

>
>Mark

Lee