[DNSOP] ordering of RRSets in the answer section of a DNS response

[Joe Abley <[e-mail]>]

Hi all,

Cloudflare's 1.1.1.1 public DNS service triggered some unexpected operational effects during a routine software release on 8 January. Sebastiaan has done a great write-up here, for those that are interested. If you happened to notice any weird spontaneous reboot loops of old enterprise switches in your network, you might be more interested than you would normally imagine.

https://blog.cloudflare.com/cname-a-record-order-dns-standards/

The nature of the trigger caused us to think a bit about ambiguity in the specification. And that trigger caused me to remember something that came up in 2015, because at the time I wrote a draft about it. I haven't taken the time to dig through the mailing list archives to figure out precisely what disturbance in the force occurred, but here's the old expired draft:

https://www.ietf.org/archive/id/draft-jabley-dnsop-ordered-answers-00.txt

Since it seemed newly pertinent, Sebastiaan and I submitted a new proposal to resolve the ambiguity in 1034/1035 (I have no good way to authorise a -01 submission for the 2015 draft, fun as it would have been to have that draft rise from the grave and walk amongst us).

https://datatracker.ietf.org/doc/draft-jabley-dnsop-ordered-answer-section/

The new draft is essentially the old draft plus references to last week's observed impact with reference to Cloudflare's comments above and a description of the impact from cisco (whose ethernet switches were the ones rebooting).

This seems to us like an uncontentious update to the DNS standard that would be useful to publish, but let us know what you think.


Joe