IPv6 automatic reverse DNS
Andrew.White2 at charter.com
Tue Nov 1 04:14:27 UTC 2016
Thanks for the info and background.
One operational suggestion I have is … why link synthesis rules to a specific DNS zone?
Most larger operators of auth DNS use an IP management tool, like BT Diamond IPAM, BlueCat, or Infoblox. Oftentimes, allocations of IP space will not be on classful boundaries, yet most often reverse DNS zones are on classful boundaries.
What may be more operationally useful would be an (optional) feature in auth DNS software that would process an incoming PTR request as follows:
1. Answer the PTR with an entry in the corresponding ip6.arpa or in-addr.arpa zone file if the PTR exists
2. Otherwise, examine a rule set of synthetic PTR responses and answer by the rule set (e.g. 10.0.0.128 matches rule for “10.0.0.128/27” and returns PTR of 10-0-0-128.dhcp.example.com.)
3. Otherwise, return NXDOMAIN or NOANSWER/NOERROR as appropriate
Such a ruleset could apply to forward zones as well to create the matching forward lookup.
Just my two cents! Caveat: personal opinion and not the official position of Charter.
Charter Network Operations - DAS DNS
Desk: 314-394-9594 - Cell: 314-452-4386
andrew.white2 at charter.com<mailto:andrew.white2 at charter.com>
From: Woodworth, John R [mailto:John.Woodworth at CenturyLink.com]
Sent: Monday, October 31, 2016 11:04 PM
To: White, Andrew; 'nanog at nanog.org'
Cc: Ballew, Dean; Woodworth, John R
Subject: RE: IPv6 automatic reverse DNS
From: NANOG [mailto:nanog-bounces at nanog.org] On Behalf Of White, Andrew
> There are two competing drafts for synthetic rule-based PTR responses
> for IPv6 rDNS:
> Howard Lee, Time Warner Cable (now Charter)
> J. Woodworth, CenturyLink
> Nominum and Xerocole/Akamai also have proprietary solutions to this
> in their Vantio AuthServ and AuthX products, respectively.
> It seems to me that it is still an open question whether the
> recommendations in RFC-1912 that any IP address that accesses the
> Internet should have a PTR and matching forward record. My personal
> thoughts are that the best solution would be an OPTIONAL standards-based
> method of generating DNS responses based on a ruleset if a specific zone
> record is not present, and that implementation of that requirement
> should be left to the developers of the auth nameserver software.
I am new to the group but one of the authors referenced above. My
colleagues and I are glad to see the discussion around this issue
see some recent movement.
As indicated by one of our esteemed WG chairs elsewhere in this thread,
I am currently working to provide additional clarity for some of the
more difficult concepts in the draft and have not yet requested the
next step. Once these changes are complete we will enthusiastically
move forward with this request.
As I am new to this forum, for the moment I wanted to simply state:
synthesized records based on the proposed "bulk rr" method can
_only_exist_where_zone_records_do_not_already_. One critical goal of
the draft is to make the "intent" of synthesized records easy to
transfer between nameservers in authoritative roles. Examples for
implementing the draft using fairly straightforward regex
manipulation are included but are more of a guideline for making
the pattern substitution easier for the implementor and provide
a reference for the accompanying examples. Ultimately, as you
recommend, the auth nameserver software vendor would be free to
provide their own pattern substitution logic (so long as the
intent is not lost).
DNSSEC for synthesized records also poses its own obvious set of…
complications for which we've outlined a number of solutions to
help satisfy this challenge.
Admittedly, it is a bit of a hefty read but we would love the
feedback (directly or in the IETF DNSOP mailing list of course).
> Caveat: These thoughts are mine personally and do not represent
> any official position of Charter Communications.
> Ληdrеw Whiте
> Charter Network Operations - DAS DNS
> Desk: 314-394-9594 ? Cell: 314-452-4386
> andrew.white2 at charter.com<mailto:andrew.white2 at charter.com>
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