nanog mailing list archives

A crazy idea


From: Stephen Satchell <list () satchell net>
Date: Mon, 19 Jul 2021 05:09:40 -0700

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:

  2600:1700:79b0:ddc0::/64
  99.65.194.96/29

The IPv6 delegation would be easy:

0.c.d.d.0.b.9.7.0.0.7.1.0.0.6.2.ip6.arpa. NS my-DNS-server-1.
0.c.d.d.0.b.9.7.0.0.7.1.0.0.6.2.ip6.arpa. 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.9.7.0.0.7.1.0.0.6.2.ip6.arpa.
@ IN SOA ...
@ NS my-DNS-server-1.
@ NS my-DNS-server-2.
1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 IN PTR server1.example.com. 2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 IN PTR server2.example.com.

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

> 96-103.194.65.99.in-addr.arpa. NS my-DNS-server-1
> 96-103.194.65.99.in-addr.arpa. NS my-DNS-server-2> $GENERATE 96-102 $ IN CNAME $.96-103.194.65.99.in-addr.arpa.

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

$ORIGIN 96-103.194.65.99.in-addr.arpa.
@ 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.


Current thread: