A crazy idea

Stephen Satchell list at satchell.net
Mon Jul 19 12:09:40 UTC 2021

First, I know this isn't the right place to propose this; need a pointer 
to where to propose an outlandish idea.

PROBLEM:  IPv6 support is still in its birthing pangs.  I see a problem 
that limits deployment of IPv6 fully:  reverse PTR records in the 
".in6.arpa." zones.

(Now that I think about it, this may very well be a network operator 
issue.  Who maintains the ".in.arpa." zones delegated by IANA now?)

I've been going 'round and 'round with AT&T about "static" IPv6 
addresses.  In particular, I can't get a PTR record in the ip6.arpa. 
zone to save my life.  Now, the problem is not really ripe yet, because 
the big reason for PTR records is for mail servers -- best practice 
calls for AAAA/PTR agreement, just like for IPv4 the best practice is 
for A/PTR agreement.

The existing DNS providers can support delegation domains, so that I 
don't have to have DNS servers of my own if I don't want to.  It could 
be that one would need to "buy" the delegation domain, but that's a 
front-office consideration.  Personally, I use register.com for my 
domain DNS zones.  I believe strongly that other registrars that offer 
customer zone editing, plus DNS service providers, can support reverse 
delegation zones with a minimum of hassle, and without charging an arm 
and a leg for the service.

 From the customers' viewpoint, a GUI would make the maintenance 
relatively painless.

(Keying the information below took a long time.  Any rational DNS admin 
and DNS service provider would have automation in place to take out the 
painful work.)

What would the domain names look like?  Let's take my current IP/IPv6 
assignments from AT&T:


The IPv6 delegation would be easy:

> 0.c.d.d.0.b. NS my-DNS-server-1.
> 0.c.d.d.0.b. NS my-DNS-server-2.

because the delegation would always be on a /64 boundary. The customer 
assignments would be straightforward.  In my BIND9 zone file, it would 
look something like this:

> $ORIGIN 0.c.d.d.0.b.
> @ IN SOA ...
> @ NS my-DNS-server-1.
> @ NS my-DNS-server-2.
> IN PTR server1.example.com. 
> IN PTR server2.example.com. 

Delegations for the IP range, not being on an octet boundary, would be a 
little more problematic:

 > 96- NS my-DNS-server-1
 > 96- NS my-DNS-server-2> $GENERATE 96-102 $ 
IN CNAME $.96-

In my BIND9 zone file, it would look something like this:

> $ORIGIN 96-
> @ SOA ...
> @ NS my-dns-server-1.
> @ NS my-dns-server-2.
> 96 IN PTR server1.example.com.
> 97 IN PTR server2.example.com.

The advantage to this system to the number providers is they would have 
one administrative record per customer, instead of having to deal with 
each PTR record individually.  The advantage to customers is they don't 
have to beg and snivel to get PTR records, just beg and snivel once to 
get the delegation.  The advantage to DNS server providers is they have 
something else to sell.

Want to encourage IPv6 adoption?  This would help.

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